wefalck

S.M.S. WESPE (HENK, 1895)
 
History and context
The WESPE-Class armoured gun-boats of the then young Imperial German Navy were born out of a tactical concept that dated well back into the Napoleonic era. The idea was to mount a heavy long-range gun onto a highly mobile small craft that would be able to retire into shallow coastal waters, beyond the range of even the heavy artillery of an attacking fleet. The addition of a steam engine and the increase in calibre followed the development of the time, of course. Adding heavy armour to the front (mainly) was meant to give the gun-boats a certain attacking capability. It also owes something to the floating batteries used in the defence of Copenhagen during the Napoleonic wars and to the armoured floating batteries used by the allied French/British forces during the Crimean War (1854-55). In fact, adding armour plating to a (rowing) gunboat was already proposed as early as the late 18th century in Spain, as documented by a model in the Museo Naval in Madrid, but apparently never put to work in full scale.
 

S.M.S. WESPE, brand-new and still without the 30.5 cm gun (1875)
 
At the time of the conception of the WESPE-class in the early 1870s a former cavalry(!) general was the naval chief-of-staff in Germany. The tactical dogma was ‘proactive defence’: an attacking enemy was to be awaited near home waters and fenced off. The main threat was seen in amphibian operations attacking the German coast. Thus, the landing of troops at strategic points had to be prevented. Long-range strategic and oceanic operations were out of the scope of the German naval planners of the time. There was a certain logic in this, as Germany, unlike Britain, is/was a more or less land-locked country and largely self-sufficient in many respects at that time. Overseas trade then did not have such an importance as in Britain or as in later globalising economies. Therefore, attempts to severe overseas supply chains was not so relevant. There was, indeed, active resistance from trade interest groups, particularly the merchants in the cities of Hamburg and Bremen, to a navy that would engage itself overseas. These merchants relied on their network of friendly contacts and on sailing under a neutral flag.
Hence, the WESPE-Class was designed to be mainly a heavily armoured gun-platform, giving long-range protection to the tidal North Sea harbours that are surrounded by mud-flats and to give mobile protection to the deep fjords of Schleswig-Holstein's Baltic coast. They would be backed-up by heavy artillery (and later fixed torpedo batteries) in coastal forts.
The guns in such boats usually could only be trained by turning the whole boat. This seems more difficult then it probably was, because even in the old days of the rowing gunboats they would attack by rowing in a wide circle and when the intended target passed through the line of aim, one would fire. As the WESPE-Class was designed to let themselves fall dry on mud-flats, a possibility to train the gun itself was needed.
This distinguished the WESPE-class from earlier boats of similar design in Britain, namely the ANT-, GADFLY-, and BOUNCER-class of the 1860s. Man other navies took up the same concept and there were examples in the Danish, Dutch, French, Norwegian, Spanish, and even the Argentinian navy. Some of the were armoured, while other were still constructed from wood or composite.
 

S.M.S. WESPE under construction (HENK, 1895)
 
Technical Description
The WESPE-class comprised ten boats delivered in two batches between 1876 and 1880: WESPE (1876), VIPER, BIENE, MÜCKE, SCORPION, BASILISK, CAMAELEON, CROCODILL, SALAMANDER and NATTER. They were all built by A.G. Weser in Bremen. With a length of 46.4 m and a beam of 10.65 m they had a dead weight of 1157 t, drawing 3.37 m. The dimensions vary somewhat according to source, but this may be due to different reference points, such as length overall compared to length between the perpendicles etc.
Two inclined double-expansion engines on two propellers gave a maximum speed of 11 knots. Their original complement was 3 officers and 73 crew. Steering was from a stand on the hut and an emergency double steering wheel abaft. Very early on they were also retrofitted with an electrical generator.
The WESPE-class were the first German warships (and indeed among the first of any warship) that did completely without auxiliary sails. As the consequence they only had a light mast for signalling. In spite of sporting quite some leading edge technology, they were only of limited seaworthiness and their handling was far from perfect. This resulted in them being given a collection of rather unfavourable nicknames. They were also not very popular with their crews and officers due to the cramped conditions below decks, but then they were not meant for long voyages in the open sea.
 

Admiralty illustrative drawing (before 1883)
 
Armament
The main armament was a single 30.5 cm rifled breech-loading gun designed and manufactured by Alfred Krupp AG in Essen. At the time the WESPE-class boats were designed, fast torpedo-boats did not exist yet – the automotive fish-torpedo was just being developed. When in the mid-1880s small torpedo-boats became a tactical reality, some form of self-defence against them was necessary and two bronce(!) 8.7 cm/l24 breech-loading guns in ‘disappearing’ carriage and two 37 mm Hotchkiss revolving guns came on board. In fact, very early on (1883) also two 35 cm underwater torpedo launching tubes were installed to increase the attacking capabilities.
 

Instruction model for the Rk 30.5/l22 on the Danish HELGOLAND in the Orlogsmuseet Copenhagen on a carriage similar to that of the WESPE-Class
 
Scale
The scale chosen for the model is 1/160, which admittedly is somewhat unusual for a ship model. However, the reasoning behind this choice was that a large selection of N-scale railway figures is available that eventually will crew the ship. There are also space and portability consideration, which are important for someone, who has to move from time to time for professional reasons.
The model will be a waterline model. This will allow a scenic presentation of the finished model. Besides, the hull below the waterline is not quite so graceful. Above the waterline the hull is also more or less prismatic, with vertical bulwarks and virtually no sheer. These parameters together call for a bread-and-butter construction.
 

Artist’s impression of a WESPE-Class gunboat (1891)
 
Sources
Owing to the loss of most of the archival material from the former Admiralty Drawing Office during and after the end of WW2, detailed source material is rather scant. Some lithographed drawings that must have been made before the major refit in 1883 have survived and serve as a basis for the reconstruction. The Bundesarchiv/Militärarchiv in Freiburg i.B. has some drawings, but unfortunatelly they only pertain to a much later refit of S.M.S. NATTER. However, the WESPE-Class was a bit of a novelty at its time and some Detaildrawings of bothm the ship and the armament, have found their way into textbooks of the time. Relatively recently a very detailed original drawing of the gun became available on the Internet from a private collection (www.dreadnoughtproject.org). Historic photographs from the early days of the ships are quite rare and mostly of not so good quality, but some reasonably good ones from the end of their active life have survived.
Based on the information that was available in the 1980s Wolfgang Bohlayer drew and published a plan of S.M.S. WESPE as she might have looked like after the major refit in 1883 (available from VTH, http://shop.vth.de/wespe-1876.html). Based on the information available today, this plan would need to be revised in some details.
The available information is summarised on the page on the WESPE-class on my Web-site: http://www.wefalck.eu/mm/maritime/models/wespe/wespeclass.html
 
To be continued ...

Thanks, gentlemen, for the encouraging comments 
 
**********
 
Milling the trunnion seats and the lock
For drilling holes for the trunnions and milling the seat of the lock the diving head was set up on the slide-rest. I could have done this operation on the milling machine, but on the lathe the dividing head (http://www.maritima-et-mechanika.org/tools/dividinghead/dividinghead.html) is centred automatically. The outer end of the barrel was supported by the arm with an appropriate centre fitted. The resulting shape from the milling operation looks like a keyhole, but something like a mushroom shape with sharp edges is required. This was achieved by hand filing.
 

Set-up showing for milling the seat for the lock
 

Close-up of the milling operation in the dividing head with support
 

Working drawing and files used to finish the lock seat
 
For the next operation the set-up had to be transferred to the mill anyway: milling the seats for the square trunnions. The trunnions merge in a concave curve with the barrel. The trunnions were turned up on the lathe as disk with two round stubs protruding from either end. In the dividing head on the mill the disk was milled square to the size of the seat (or rather the other way round). These parts then were soft-soldered to the barrel. Back on the mill the concave curves of the square part of the trunnion were milled using a miniature ball-head cutter, rotating the barrel in the dividing head.
 

Milling the square part of the trunnions
 

Milling the seat for the trunnions
 

Trying the trunnion
 

Milling the concave transition between trunnion and barrel
 
Aiming a gun in these days was a rather primitive affair, using just simple sights. The sights (two of them on either side of the barrel) consisted essentially of a round bar with a sliding rod to give the elevation. The beads (mounted near the trunnions) were observed through a ring of inverted U-shape on top of the rod. The bar was screwed into a notch in the barrel. Now, drilling into a round at a tangent is nearly impossible without deflection and breaking the drill (0.3 mm!). Therefore, I ground flat a broken drill bit to make a make-shift micro-mill and sunk a start hole. This was finished with an ordinary drill.
 

Milling the seat for the sights
 

Drilling the seats for the sights
 
To be continued ...

Thanks, gentlemen, for the encouraging comments 
 
**********
 
Milling the trunnion seats and the lock
For drilling holes for the trunnions and milling the seat of the lock the diving head was set up on the slide-rest. I could have done this operation on the milling machine, but on the lathe the dividing head (http://www.maritima-et-mechanika.org/tools/dividinghead/dividinghead.html) is centred automatically. The outer end of the barrel was supported by the arm with an appropriate centre fitted. The resulting shape from the milling operation looks like a keyhole, but something like a mushroom shape with sharp edges is required. This was achieved by hand filing.
 

Set-up showing for milling the seat for the lock
 

Close-up of the milling operation in the dividing head with support
 

Working drawing and files used to finish the lock seat
 
For the next operation the set-up had to be transferred to the mill anyway: milling the seats for the square trunnions. The trunnions merge in a concave curve with the barrel. The trunnions were turned up on the lathe as disk with two round stubs protruding from either end. In the dividing head on the mill the disk was milled square to the size of the seat (or rather the other way round). These parts then were soft-soldered to the barrel. Back on the mill the concave curves of the square part of the trunnion were milled using a miniature ball-head cutter, rotating the barrel in the dividing head.
 

Milling the square part of the trunnions
 

Milling the seat for the trunnions
 

Trying the trunnion
 

Milling the concave transition between trunnion and barrel
 
Aiming a gun in these days was a rather primitive affair, using just simple sights. The sights (two of them on either side of the barrel) consisted essentially of a round bar with a sliding rod to give the elevation. The beads (mounted near the trunnions) were observed through a ring of inverted U-shape on top of the rod. The bar was screwed into a notch in the barrel. Now, drilling into a round at a tangent is nearly impossible without deflection and breaking the drill (0.3 mm!). Therefore, I ground flat a broken drill bit to make a make-shift micro-mill and sunk a start hole. This was finished with an ordinary drill.
 

Milling the seat for the sights
 

Drilling the seats for the sights
 
To be continued ...

Thanks, gentlemen, for the encouraging comments 
 
**********
 
Milling the trunnion seats and the lock
For drilling holes for the trunnions and milling the seat of the lock the diving head was set up on the slide-rest. I could have done this operation on the milling machine, but on the lathe the dividing head (http://www.maritima-et-mechanika.org/tools/dividinghead/dividinghead.html) is centred automatically. The outer end of the barrel was supported by the arm with an appropriate centre fitted. The resulting shape from the milling operation looks like a keyhole, but something like a mushroom shape with sharp edges is required. This was achieved by hand filing.
 

Set-up showing for milling the seat for the lock
 

Close-up of the milling operation in the dividing head with support
 

Working drawing and files used to finish the lock seat
 
For the next operation the set-up had to be transferred to the mill anyway: milling the seats for the square trunnions. The trunnions merge in a concave curve with the barrel. The trunnions were turned up on the lathe as disk with two round stubs protruding from either end. In the dividing head on the mill the disk was milled square to the size of the seat (or rather the other way round). These parts then were soft-soldered to the barrel. Back on the mill the concave curves of the square part of the trunnion were milled using a miniature ball-head cutter, rotating the barrel in the dividing head.
 

Milling the square part of the trunnions
 

Milling the seat for the trunnions
 

Trying the trunnion
 

Milling the concave transition between trunnion and barrel
 
Aiming a gun in these days was a rather primitive affair, using just simple sights. The sights (two of them on either side of the barrel) consisted essentially of a round bar with a sliding rod to give the elevation. The beads (mounted near the trunnions) were observed through a ring of inverted U-shape on top of the rod. The bar was screwed into a notch in the barrel. Now, drilling into a round at a tangent is nearly impossible without deflection and breaking the drill (0.3 mm!). Therefore, I ground flat a broken drill bit to make a make-shift micro-mill and sunk a start hole. This was finished with an ordinary drill.
 

Milling the seat for the sights
 

Drilling the seats for the sights
 
To be continued ...

Thanks, gentlemen, for the encouraging comments 
 
**********
 
Milling the trunnion seats and the lock
For drilling holes for the trunnions and milling the seat of the lock the diving head was set up on the slide-rest. I could have done this operation on the milling machine, but on the lathe the dividing head (http://www.maritima-et-mechanika.org/tools/dividinghead/dividinghead.html) is centred automatically. The outer end of the barrel was supported by the arm with an appropriate centre fitted. The resulting shape from the milling operation looks like a keyhole, but something like a mushroom shape with sharp edges is required. This was achieved by hand filing.
 

Set-up showing for milling the seat for the lock
 

Close-up of the milling operation in the dividing head with support
 

Working drawing and files used to finish the lock seat
 
For the next operation the set-up had to be transferred to the mill anyway: milling the seats for the square trunnions. The trunnions merge in a concave curve with the barrel. The trunnions were turned up on the lathe as disk with two round stubs protruding from either end. In the dividing head on the mill the disk was milled square to the size of the seat (or rather the other way round). These parts then were soft-soldered to the barrel. Back on the mill the concave curves of the square part of the trunnion were milled using a miniature ball-head cutter, rotating the barrel in the dividing head.
 

Milling the square part of the trunnions
 

Milling the seat for the trunnions
 

Trying the trunnion
 

Milling the concave transition between trunnion and barrel
 
Aiming a gun in these days was a rather primitive affair, using just simple sights. The sights (two of them on either side of the barrel) consisted essentially of a round bar with a sliding rod to give the elevation. The beads (mounted near the trunnions) were observed through a ring of inverted U-shape on top of the rod. The bar was screwed into a notch in the barrel. Now, drilling into a round at a tangent is nearly impossible without deflection and breaking the drill (0.3 mm!). Therefore, I ground flat a broken drill bit to make a make-shift micro-mill and sunk a start hole. This was finished with an ordinary drill.
 

Milling the seat for the sights
 

Drilling the seats for the sights
 
To be continued ...

@bear, I must say, you rather embarrass me with your praise   I gather, a professional mechanic would throw up his hands into the air seeing me doing things, being just a self-taught amateur. Actually, collecting old machine tools and their restoration developed into a hobby of its own: http://www.maritima-et-mechanika.org/tools/toolsmain.html
 
********
Back to the subject ….
 
Rack-and-pinion drive for training the gun
 
The gun was trained by pinion acting on a circular rack. The pinion was driven from under deck by a sets of gears and a couple of cranks manned by a number of sailors. The chief gunner was able to connect and disconnect the drive with levers from his aiming-stand behind the gun.
I set up my hand-shaper (http://www.wefalck.eu/mm/tools/shaper/shapers.html) for cutting the rack teeth, but had to throw away the first two attempts because of the poor material and because - again against better knowledge - I did not lock the traverse slide when cutting. The table was removed from the shaper and the home-made dividing head bolted on instead. For lack of a proper tool grinder (another project now in hand) I hand-ground a cutter for the rack teeth (0.1 mm at the bottom) from a rod of high-speed steel. For holding this tool-bit in the shaper, an old lantern-style tool holder from the watch lathe came very handy. The unwanted parts of the ring were cut away on the shaper using ordinary left and right hand lathe tools. Finally the necessary sections were trimmed off with a fine saw blade on the lathe's sawing table.
 

Hand-shaper set-up for cutting the toothed rack
 

Cutting the toothed rack with a specially ground tool
 

Cutting away the unwanted part of the ring with an ordinary tool
 

Rails and rack provisionally in their place inside the barbette
 
 
To be continued ...

Thanks, gentlemen, for the encouraging comments 
 
**********
 
Milling the trunnion seats and the lock
For drilling holes for the trunnions and milling the seat of the lock the diving head was set up on the slide-rest. I could have done this operation on the milling machine, but on the lathe the dividing head (http://www.maritima-et-mechanika.org/tools/dividinghead/dividinghead.html) is centred automatically. The outer end of the barrel was supported by the arm with an appropriate centre fitted. The resulting shape from the milling operation looks like a keyhole, but something like a mushroom shape with sharp edges is required. This was achieved by hand filing.
 

Set-up showing for milling the seat for the lock
 

Close-up of the milling operation in the dividing head with support
 

Working drawing and files used to finish the lock seat
 
For the next operation the set-up had to be transferred to the mill anyway: milling the seats for the square trunnions. The trunnions merge in a concave curve with the barrel. The trunnions were turned up on the lathe as disk with two round stubs protruding from either end. In the dividing head on the mill the disk was milled square to the size of the seat (or rather the other way round). These parts then were soft-soldered to the barrel. Back on the mill the concave curves of the square part of the trunnion were milled using a miniature ball-head cutter, rotating the barrel in the dividing head.
 

Milling the square part of the trunnions
 

Milling the seat for the trunnions
 

Trying the trunnion
 

Milling the concave transition between trunnion and barrel
 
Aiming a gun in these days was a rather primitive affair, using just simple sights. The sights (two of them on either side of the barrel) consisted essentially of a round bar with a sliding rod to give the elevation. The beads (mounted near the trunnions) were observed through a ring of inverted U-shape on top of the rod. The bar was screwed into a notch in the barrel. Now, drilling into a round at a tangent is nearly impossible without deflection and breaking the drill (0.3 mm!). Therefore, I ground flat a broken drill bit to make a make-shift micro-mill and sunk a start hole. This was finished with an ordinary drill.
 

Milling the seat for the sights
 

Drilling the seats for the sights
 
To be continued ...

These appear to be artistic representations of a certain Aldo Cherini. He has been very busy, but unfortunately, he does not give any sources for his drawings, so that it is impossible to ascertain their correctness.
 
Some people actually do model pacific boats:
 
http://www.maritima-et-mechanika.org/maritime/models/ellice/ellicecanoe.html
 
http://www.maritima-et-mechanika.org/maritime/models/gilbert/gilbertcanoe.html
 
  

And the show goes on ...
 
**************
 
The gun barrel and lock
Turning the barrel
Because there will various visible areas of bare metal, the material of the original, that is steel, was chosen.  A piece of round bar was faced, centred and rough drilled for the bore. This hole served as a protective counter bore for the tailstock centre during the following turning operations. In order to get a good finish the automatic longitudinal feed for the lathe was set up with the change gears. Unfortunately the minimum feed per revolution on the watchmaking lathe is still too high to get a 'mirror' finish. One day I have to construct some sort of reduction gear. The outer part of the barrel has a slight taper (1 degree included angle) and the top-slide was off-set accordingly for this operation.
 

Facing and centring a piece of steel rod for the gun barrel
 

Rough drilling of the gun barrel
 

Turning the barrel using the automatic fine feed
 

Taper-turning with slide rest off-set
 
For rounding off the ends of the rings the lathe’s hand tool rest came to good use. The work was finished off with fine wet-and-dry paper (remember to cover ways!) and steel wool. The bore was bored to diameter using the slide-rest and a micro-boring tool. I had originally envisaged to also show the rifling, but a quick calculation told me that for a 1 mm bore and 72 rifled fields I would need a tool edge tha is just over 0.04 mm wide ...
 

Rounding the 'rings' using a hand turning rest
 

Boring the barrel using a micro boring tool
 
To be continued ...

@bear, I must say, you rather embarrass me with your praise   I gather, a professional mechanic would throw up his hands into the air seeing me doing things, being just a self-taught amateur. Actually, collecting old machine tools and their restoration developed into a hobby of its own: http://www.maritima-et-mechanika.org/tools/toolsmain.html
 
********
Back to the subject ….
 
Rack-and-pinion drive for training the gun
 
The gun was trained by pinion acting on a circular rack. The pinion was driven from under deck by a sets of gears and a couple of cranks manned by a number of sailors. The chief gunner was able to connect and disconnect the drive with levers from his aiming-stand behind the gun.
I set up my hand-shaper (http://www.wefalck.eu/mm/tools/shaper/shapers.html) for cutting the rack teeth, but had to throw away the first two attempts because of the poor material and because - again against better knowledge - I did not lock the traverse slide when cutting. The table was removed from the shaper and the home-made dividing head bolted on instead. For lack of a proper tool grinder (another project now in hand) I hand-ground a cutter for the rack teeth (0.1 mm at the bottom) from a rod of high-speed steel. For holding this tool-bit in the shaper, an old lantern-style tool holder from the watch lathe came very handy. The unwanted parts of the ring were cut away on the shaper using ordinary left and right hand lathe tools. Finally the necessary sections were trimmed off with a fine saw blade on the lathe's sawing table.
 

Hand-shaper set-up for cutting the toothed rack
 

Cutting the toothed rack with a specially ground tool
 

Cutting away the unwanted part of the ring with an ordinary tool
 

Rails and rack provisionally in their place inside the barbette
 
 
To be continued ...

And the show goes on ...
 
**************
 
The gun barrel and lock
Turning the barrel
Because there will various visible areas of bare metal, the material of the original, that is steel, was chosen.  A piece of round bar was faced, centred and rough drilled for the bore. This hole served as a protective counter bore for the tailstock centre during the following turning operations. In order to get a good finish the automatic longitudinal feed for the lathe was set up with the change gears. Unfortunately the minimum feed per revolution on the watchmaking lathe is still too high to get a 'mirror' finish. One day I have to construct some sort of reduction gear. The outer part of the barrel has a slight taper (1 degree included angle) and the top-slide was off-set accordingly for this operation.
 

Facing and centring a piece of steel rod for the gun barrel
 

Rough drilling of the gun barrel
 

Turning the barrel using the automatic fine feed
 

Taper-turning with slide rest off-set
 
For rounding off the ends of the rings the lathe’s hand tool rest came to good use. The work was finished off with fine wet-and-dry paper (remember to cover ways!) and steel wool. The bore was bored to diameter using the slide-rest and a micro-boring tool. I had originally envisaged to also show the rifling, but a quick calculation told me that for a 1 mm bore and 72 rifled fields I would need a tool edge tha is just over 0.04 mm wide ...
 

Rounding the 'rings' using a hand turning rest
 

Boring the barrel using a micro boring tool
 
To be continued ...

@bear, I must say, you rather embarrass me with your praise   I gather, a professional mechanic would throw up his hands into the air seeing me doing things, being just a self-taught amateur. Actually, collecting old machine tools and their restoration developed into a hobby of its own: http://www.maritima-et-mechanika.org/tools/toolsmain.html
 
********
Back to the subject ….
 
Rack-and-pinion drive for training the gun
 
The gun was trained by pinion acting on a circular rack. The pinion was driven from under deck by a sets of gears and a couple of cranks manned by a number of sailors. The chief gunner was able to connect and disconnect the drive with levers from his aiming-stand behind the gun.
I set up my hand-shaper (http://www.wefalck.eu/mm/tools/shaper/shapers.html) for cutting the rack teeth, but had to throw away the first two attempts because of the poor material and because - again against better knowledge - I did not lock the traverse slide when cutting. The table was removed from the shaper and the home-made dividing head bolted on instead. For lack of a proper tool grinder (another project now in hand) I hand-ground a cutter for the rack teeth (0.1 mm at the bottom) from a rod of high-speed steel. For holding this tool-bit in the shaper, an old lantern-style tool holder from the watch lathe came very handy. The unwanted parts of the ring were cut away on the shaper using ordinary left and right hand lathe tools. Finally the necessary sections were trimmed off with a fine saw blade on the lathe's sawing table.
 

Hand-shaper set-up for cutting the toothed rack
 

Cutting the toothed rack with a specially ground tool
 

Cutting away the unwanted part of the ring with an ordinary tool
 

Rails and rack provisionally in their place inside the barbette
 
 
To be continued ...

The 30.5 cm Rk/l22 gun
 
The main armament of the WESPE-Class was a massive 30.5 cm (12”) Krupp breech-loading rifled gun (Ringkanone, abrev. Rk). This caliber stayed the bigges in the German Imperial Navy for many decades and well into the Dreadnought-era. It is this gun that essentailly made the boats in floating batteries, rather than ‘real’ ships.
 
http://www.dreadnoughtproject.org)
 
A few years ago a detailed dtawing of gun-mount originating in the adminralty archives in Berlin surfaced on the site ‘dreadnought’. The arrangements for all the heavy Krupp guns of the time were similar, so that a visit to the Finnish fortress Suomenlinna (http://www.maritima-et-mechanika.org/maritime/models/wespe/suomenlinna/suomenlinna.html) off Helsinki was helpful; here a number of Russian clones of 28 cm coastal Krupp guns are still in place since the time, when Finnland was part of the Russian Empire.
 

28 cm Krupp-clone coastal guns in the Suomenlinna-fortress off Helsinki
 
Rails for the Lower Carriage
The lower carriage of the gun is supported on four races that run on semicirucular cast-iron rails bolted to the deck inside the barbette.
These rails need to go into their place in the barbette early during the construction. The same applies to the semi-circular toothed rack that is part of the gun-training machinery. I decided to make the rails from steel, even though ferrous metals in model construction are frowned upon by many. My justifications were that it is difficult to represent cast iron or steel by paint and that there hundreds of models in museums around the world that contain iron. I have used steel in models some twenty years ago and presumably due to the lacquering they shows no signs of rust.
 

Roughing out the rails from a metal disc with the backing of a wooden disc
 

Grooving the races with a specially ground bit
 
Cutting thin disks from round stock of large diameter is a pain I wanted to avoid. Against my better knowledge I picked a suitably sized steel washer as starting material. Unfortunately, the steel used did not machine very well and lot effort was spent to avoid chatter marks while turning and to obtain a reasonably good finish. The various types of wheel collets and chucks available for the watchmaking lathe came into good use for working on inside and outside diameters of these discs. The rails were shaped using a specially ground forming tool.
 

Cutting out the inside of the large ring for the tail-races of the lower carriage, while holding it in a so-called bezel-chuck
 

Trimming the outside of the smaller forward ring holding the material in a so-called wheel-chuck
 

The rails laid out in the barbette
 
To be continued ...

Yes, Plexiglas is a nice material to machine. I have been making small deck-houses etc. with this method since the late 1970s. My late father worked for a sister company to that manufactured Plexiglas (Röhm GmbH) and we had easy access to it in all sizes and shapes. Röhm GmbH also produced a comprehensive technical manual for working with Plexiglas, of which I have a copy - very useful.

Engine-room skylight
 
The frame of the engine room skylight consists of a an etched brass part, folded up and soldered together. On the inside, grooves have been etched that will serve to locate the protective bars to made from thin copper wire. The lower frame was constructed from Pertinax. The ‘wooden’ gratings on both sides of the lower frame are again etched parts.
 

Unglazed framework for the engine-room skylight
 
Once this structure was complete, a square block of the size of the footprint of the skylight was milled from a piece of Plexiglas.
 

Squaring up a Plexiglas block for the skylight
 
In the next step the roof-shaped faces were milled on. To this end, a small insert vice was set to the appropriate angle of 40° in a larger vice bolted to the mill table. The fixed jaw of the insert vice pointed upward and the side of the block to be milled rested against it. This ensured that all four inclined faces would have the same angle and would start from the same height with respect to the reference (bottom) face of the block.
 

Milling the sloping faces
 

Polishing the sloping faces  
 
A very smooth surface with little tool marks can be achieved on Plexiglas. The final polishing of the surfaces was done using CRATEX-type drum polishers followed by a felt drum loaded with polishing paste. All in the same vice setting to ensure a flat surface. I was lucky the Plexiglas 'house' fitted like a plug into the skylight frame.
 

Finished Plexiglas 'glazing' block
 

Glazed engine room skylight
 
To be continued ...

Chain-stoppers
 
One pair of chain stoppers is located immediately behind the hawse pipes as usual. A second pair is placed above the chain locker, which is located immediately in from of the armoured barbette. The bodies of the stoppers are rather complex castings, calling for some complex machining operations in model reproduction. The same basic technique as for the bollards was used. Given the complex shape, however, machining is not possible in one set-up. For certain operations the axis of the spigot has to be perpendicular to the milling machine, while for others, such as drilling it has to be parallel. For the latter and for milling the various slots, I choose to transfer the dividing head to the lathe. This has the advantage that its centre line is at the centre of the lathe spindle.
 

Milling the profile of the fore chain stoppers
 

Milling operations using a dividing head in the lathe
 
The slots were milled using a micro-tool made from a broken carbide drill, the end of which was ground flat. This results in a non-ideal clearance of 0º, while the cutting angle and side rake are that of the original drill bit. However, not much metal is removed so that this doesn't really matter here.
 

Home-made milling bits made from broken carbide drills ground flat
 
One set of stoppers was milled from brass, while for the other one I used PMMA (PLEXIGLAS®, PERSPEX), the main reason being that I ran out of brass stock. However, genuine PLEXIGLAS®, is pleasant material to machine and easy on the tools. It holds sharp edges and it easier to see what you are doing than on the shiny brass. Acrylic paints seem to key-in well - basically it is the same molecule, of course. On the downside one may note that small and thin parts are rather brittle. Using diamond-cut carbide tools gives a nice smooth finish, but normal CV- or HSS-tools can also be used.
 

Milling in an upright collet-holder on the milling machine
 
While for the bollards and the front pair of stoppers the spigot could be on the geometric centre of the part, making it easy to measure while machining, for the after stoppers I had to place the spigot to the centre of the pipe down to the locker, so that the concentric rounded edges could be milled. The pictures show this operation.
 

Round-milling the body of the after chain-stopper using the rotary table of the milling machine
 
The stoppers have now completed with etched brass releasing levers, etc. The fore stoppers were also soldered to surface etched base plates.
 

The completed chain-stoppers (right column, the grid of the cutting mat is 10 mm x 10 mm)
 
To be continued ...

Working close to the collet improves precision due to less run-out and side-play, which are minimal on a watchmaker's lathe already ...
 
*******
 
Completing the capstan
Again the guiding rollers are a simple turning job. The shapes were produced with a free-turning graver and by rotary milling in the dividing head.
 

Using a worm-driven dividing head to round-mill the head of the chain-rollers
 

Using a worm-driven dividing head to round-mill the head of the chain-rollers
 
In the meantime various etched parts had been produced, including the base plate made up of two different superimposed parts and minuscule pawls. Also a chain separator from 0.3 mm copper wire rolled flat was produced. The various parts were soldered together.
 

The etched parts for the spills
 

The completed capstan (lower left corner, the grid of the cutting mat is 10 mm x 10 mm)
 
To be continued ...

Yes, the squares on the cutting mat are 10 x 10 mm ...
 
*******
 
Anchor capstan
One component that always has puzzled me somewhat as to their manufacture in a model has been the sprocket on capstans. While the geometry on horizontal windlasses is quite simple, with suitable depressions for the chain links around the circumference, the sprocket on a capstan is a complex affair. In any case the capstan head cannot be manufactured in one piece. So I broke it down into three pieces: the spill head, the sprocket and the base drum with the pawls. The whole capstan has more pieces including four guiding rollers and a finger to pull the chain off the sprocket. The cast base on the prototype will be reproduced as a surface-etched part.
 

Milling the sprocket, 1st step
 

Milling the sprocket, 2nd step
 
The sprocket started out as a 2.5 mm brass rod taken into the dividing head and five notches were milled to produce something like a five-pointed star (these sprockets typically have five or six arms). The notches for the horizontal links were cut on the lathe with a forming tool. The sprocket then was faced and drilled to fit onto the capstan stem. The next step is cutting it off. This produces some burrs that need to be taken off. Luckily I have collected over the years almost every type of work-holding device that was ever made for the watchmakers lathe. Here the insert jewel chucks came handy to hold the 2.2 mm by 0.6 mm sprocket for facing-off.
 

Cutting with a forming tool
 

Facing-off the sprocket in a jewel chuck
 
The capstan head is a simple turning job. The curved surfaces are pre-cut with appropriate lathe tools and then finished with very fine files. Incidentally, the implement shown on the appropriate picture is a rare miniature micrometer, also coming from the watchmakers toolbox and very handy for measuring narrow recesses and the likes. They came in sets of three, the other two are a depth-micrometer and one for measuring the width of notches respectively.
Finally, the three parts are soft-soldered together.
 

Assembled capstan head
 
To be continued ...

Deck Fittings
The hull taking shape, at least in its rough outline, I turned my attention to some pieces of deck fittings. I know, many modellers more or less complete the hulls etc. including the paintwork first, but as many pieces may require repeated handling and fitting on the hull, I leave these finishing touches to the end.
 
Bollards
The ships were fitted with four pairs of bollards of square cross section; two at the rear and two on the raised quarterdeck. Luckily a good, rather close-up photograph of the real specimen is available.
 

Rear deck with emergency steering stand and other pieces of deck fittings
 
The bollards are milled from round brass stock. Round stock was chosen as a starting point rather than e.g. flat stock, because it can be held easily in the lathe for turning on a spigot, by which the part can be held for further machining. Otherwise it would be difficult to mount such a small part on the miller for machining on five sides. The spigot is a convenient reference for machining and for fastening the part on the model eventually.
 

Indexing head on the milling machine
 

Before the milling operations
 
From the lathe the raw part is transferred to an indexing head mounted on the milling machine. After each pass with the cutting tool, the part is turned by 90º or 180º depending on requirements. Thus a square and symmetric part is produced.
 

Milling nearly completed
 
For a final machining step, the part is transferred back to the lathe and the dome shaped head formed using a very fine file on a roller-filing rest.
 

The nearly finished bollard with the roller-filing rest in the foreground
 
The job is completed by rounding off the corners using a not-too-hard rubber-bonded abrasive wheel (CRATEX) in the mini-drill. Remaining machining burrs are removed by offering the part to wire brush wheel.
 

The bollards on part of the working drawing
 
To be continued with the bases for the bollards ...

The Barbette for the 30.5 cm Gun
The barbette mainly consists of a semi-circular breastwork armour, backed by hardwood and by an open space covered with thin plate. The latter presumably to retain splintering wood in case of an impact. Since no tube of suitable dimensions for the breastwork was to hand, I made a short, laminated one from Bristol board layers glued together with white glue. The edges were soaked in thinned white glue before being trimmed down on the lathe. The tube then was varnished with wood-filler before the edges were sanded. Finally the tube was cut into half on the fret-saw. More wood-filler was applied before final sanding. The other inside wall of the barbette were lined with Pertinax to provide a smooth surface.
 

Trimming the laminated tube on the lathe
 
The fore-deck has been covered in a sheet of thin Bristol board and the camber of the wooden decking built up with an additional piece of board and putty (I am using fast drying bodywork putty from car repair suppliers). The anchor pockets have also been lined with thin Bristol board, but Pertinax would have been better for this.
 

Tube for the barbette armour made from laminated Bristol board
 
All surfaces that would have been iron plating, will be covered in thin sheets of Pertinax. The necessary holes for portholes and other opening will be drilled or cut before the sheets are fixed.
In between, I had also improvised a disc-sander from a PROXXON router. In think in the meantime this manufacturer offers a small disc-sander.
 

Smoothing the hull on the newly constructed disc sander
 
To be continued ...

@Tadheus, thank you very much for your efforts ! However, could you please check on my Web-site first, before posting a link, whether the picture you found has not been already published there. These pictures are all well-known to me and I may want to use them later to illustrate specific points.
 
*******
 
And off we go with the actual model construction ...
 
Materials
 
I had been contemplating a variety of materials for the hull; for instance Plexiglas® layers with bulwarks made from brass foil. In the end, I choose MDF (medium-density fibre) board, which is available in thicknesses down to 1 mm from architectural model supply houses. Other parts will be constructed from or covered with Bristol board, which is also available in various thicknesses (or rather weights per square metre). The bulwarks etc.. will be made from Pertinax® (phenolic resin impregnated paper, FR-2), which is available in thicknesses down to 0.1 mm. Bristol board and Pertinax® are easily cut with a scalpel, a razor blade or scissors and will not crease or dent as metal foil might. I currently have no facilities for photo-etching large parts, but if I had, perhaps I would have made the bulwarks from brass still. The other advantage is that Bristol board can be readily and permanently glued using white glue. Bonds between large areas of metal foil and Plexiglas® might become detached. Pertinax® can be glued using cyano-acrylate or epoxy-resins.
While I have been shying away from thermoplastics, such as polystyrene, on account of it being suspicious to be not ‘permanent’, practical experience shows that my plastic models built over 40 years ago are still intact. So I may reconsider my position in this respect. Polystyrene, of course, has several advantageous properties. One has to be sure, however, that it is properly painted to exclude the deteriorating UV-radiation.
 
The hull and superstructures
 
The basic bread-and-butter construction of the hull is shown in the pictures below.
 

Cutting out layers for the hull
 

Using the drill press as a makeshift disc sander (I have since constructed one)
 

Using the drill press as an improvised miniature drum sander
 

The layers of the hull with the barbette and the anchor-pockets cut out
 

Milling a recess into which later the rubbing strake will be inserted
 
To be continued ...

Looking at my records, I realised that I started the project already in 2006, after doing some 10 or more years of research on it. I also began to report on the project in MSW 1.0, but this building report sank together with it and the project then stalled due to my move to Paris. Now, with my Noord-Holland nostalgia Botter-project all but completed, I am turning my attention to the WESPE again. Looking over its storage box, I realised that I had made quite a few bits and pieces already, on which I will report here by and by.
 
@tadheus: thanks for the picture. This wellknown picture shows some of the boats towards the end of their active service life in one of the entrance locks to Wilhelmshaven harbour. While I will be depicting the boats in a state some 20 years earlier, this photograph is very useful, because it is one of the few close-up images showing a lot of detail.
 
As to the scale: I chose the 1:160 scale really for three reasons: i) I don't have the space to keep large models and I don't like to give my models away, once completed; ii) I like the challenge of working at a small scale, trying to pack-in us much detail as others may do at twice the size; iii) this is the model-railway N-scale, so you can crew water-line models easily.
 
There is also a German Wikipedia-page on these boats: http://de.wikipedia.org/wiki/SMS_Wespe_(1876) and a generic page on 'flat-iron' gunboats, as they were also called: http://en.wikipedia.org/wiki/Flat-iron_gunboat. Both pages, however, have to be taken with a pinch of salt, as they contain some imprecisions.

S.M.S. WESPE (HENK, 1895)
 
History and context
The WESPE-Class armoured gun-boats of the then young Imperial German Navy were born out of a tactical concept that dated well back into the Napoleonic era. The idea was to mount a heavy long-range gun onto a highly mobile small craft that would be able to retire into shallow coastal waters, beyond the range of even the heavy artillery of an attacking fleet. The addition of a steam engine and the increase in calibre followed the development of the time, of course. Adding heavy armour to the front (mainly) was meant to give the gun-boats a certain attacking capability. It also owes something to the floating batteries used in the defence of Copenhagen during the Napoleonic wars and to the armoured floating batteries used by the allied French/British forces during the Crimean War (1854-55). In fact, adding armour plating to a (rowing) gunboat was already proposed as early as the late 18th century in Spain, as documented by a model in the Museo Naval in Madrid, but apparently never put to work in full scale.
 

S.M.S. WESPE, brand-new and still without the 30.5 cm gun (1875)
 
At the time of the conception of the WESPE-class in the early 1870s a former cavalry(!) general was the naval chief-of-staff in Germany. The tactical dogma was ‘proactive defence’: an attacking enemy was to be awaited near home waters and fenced off. The main threat was seen in amphibian operations attacking the German coast. Thus, the landing of troops at strategic points had to be prevented. Long-range strategic and oceanic operations were out of the scope of the German naval planners of the time. There was a certain logic in this, as Germany, unlike Britain, is/was a more or less land-locked country and largely self-sufficient in many respects at that time. Overseas trade then did not have such an importance as in Britain or as in later globalising economies. Therefore, attempts to severe overseas supply chains was not so relevant. There was, indeed, active resistance from trade interest groups, particularly the merchants in the cities of Hamburg and Bremen, to a navy that would engage itself overseas. These merchants relied on their network of friendly contacts and on sailing under a neutral flag.
Hence, the WESPE-Class was designed to be mainly a heavily armoured gun-platform, giving long-range protection to the tidal North Sea harbours that are surrounded by mud-flats and to give mobile protection to the deep fjords of Schleswig-Holstein's Baltic coast. They would be backed-up by heavy artillery (and later fixed torpedo batteries) in coastal forts.
The guns in such boats usually could only be trained by turning the whole boat. This seems more difficult then it probably was, because even in the old days of the rowing gunboats they would attack by rowing in a wide circle and when the intended target passed through the line of aim, one would fire. As the WESPE-Class was designed to let themselves fall dry on mud-flats, a possibility to train the gun itself was needed.
This distinguished the WESPE-class from earlier boats of similar design in Britain, namely the ANT-, GADFLY-, and BOUNCER-class of the 1860s. Man other navies took up the same concept and there were examples in the Danish, Dutch, French, Norwegian, Spanish, and even the Argentinian navy. Some of the were armoured, while other were still constructed from wood or composite.
 

S.M.S. WESPE under construction (HENK, 1895)
 
Technical Description
The WESPE-class comprised ten boats delivered in two batches between 1876 and 1880: WESPE (1876), VIPER, BIENE, MÜCKE, SCORPION, BASILISK, CAMAELEON, CROCODILL, SALAMANDER and NATTER. They were all built by A.G. Weser in Bremen. With a length of 46.4 m and a beam of 10.65 m they had a dead weight of 1157 t, drawing 3.37 m. The dimensions vary somewhat according to source, but this may be due to different reference points, such as length overall compared to length between the perpendicles etc.
Two inclined double-expansion engines on two propellers gave a maximum speed of 11 knots. Their original complement was 3 officers and 73 crew. Steering was from a stand on the hut and an emergency double steering wheel abaft. Very early on they were also retrofitted with an electrical generator.
The WESPE-class were the first German warships (and indeed among the first of any warship) that did completely without auxiliary sails. As the consequence they only had a light mast for signalling. In spite of sporting quite some leading edge technology, they were only of limited seaworthiness and their handling was far from perfect. This resulted in them being given a collection of rather unfavourable nicknames. They were also not very popular with their crews and officers due to the cramped conditions below decks, but then they were not meant for long voyages in the open sea.
 

Admiralty illustrative drawing (before 1883)
 
Armament
The main armament was a single 30.5 cm rifled breech-loading gun designed and manufactured by Alfred Krupp AG in Essen. At the time the WESPE-class boats were designed, fast torpedo-boats did not exist yet – the automotive fish-torpedo was just being developed. When in the mid-1880s small torpedo-boats became a tactical reality, some form of self-defence against them was necessary and two bronce(!) 8.7 cm/l24 breech-loading guns in ‘disappearing’ carriage and two 37 mm Hotchkiss revolving guns came on board. In fact, very early on (1883) also two 35 cm underwater torpedo launching tubes were installed to increase the attacking capabilities.
 

Instruction model for the Rk 30.5/l22 on the Danish HELGOLAND in the Orlogsmuseet Copenhagen on a carriage similar to that of the WESPE-Class
 
Scale
The scale chosen for the model is 1/160, which admittedly is somewhat unusual for a ship model. However, the reasoning behind this choice was that a large selection of N-scale railway figures is available that eventually will crew the ship. There are also space and portability consideration, which are important for someone, who has to move from time to time for professional reasons.
The model will be a waterline model. This will allow a scenic presentation of the finished model. Besides, the hull below the waterline is not quite so graceful. Above the waterline the hull is also more or less prismatic, with vertical bulwarks and virtually no sheer. These parameters together call for a bread-and-butter construction.
 

Artist’s impression of a WESPE-Class gunboat (1891)
 
Sources
Owing to the loss of most of the archival material from the former Admiralty Drawing Office during and after the end of WW2, detailed source material is rather scant. Some lithographed drawings that must have been made before the major refit in 1883 have survived and serve as a basis for the reconstruction. The Bundesarchiv/Militärarchiv in Freiburg i.B. has some drawings, but unfortunatelly they only pertain to a much later refit of S.M.S. NATTER. However, the WESPE-Class was a bit of a novelty at its time and some Detaildrawings of bothm the ship and the armament, have found their way into textbooks of the time. Relatively recently a very detailed original drawing of the gun became available on the Internet from a private collection (www.dreadnoughtproject.org). Historic photographs from the early days of the ships are quite rare and mostly of not so good quality, but some reasonably good ones from the end of their active life have survived.
Based on the information that was available in the 1980s Wolfgang Bohlayer drew and published a plan of S.M.S. WESPE as she might have looked like after the major refit in 1883 (available from VTH, http://shop.vth.de/wespe-1876.html). Based on the information available today, this plan would need to be revised in some details.
The available information is summarised on the page on the WESPE-class on my Web-site: http://www.wefalck.eu/mm/maritime/models/wespe/wespeclass.html
 
To be continued ...

Thanks 
 
*************
 
Skylights, Companionways etc.   I have used two basic techniques for the construction of skylights, companioways etc., depending of the type and purpose. Skylights particularly were constructed around small blocks of Plexiglas milled to shape. Other types were constructed from strips of Pertinax. More intricate parts were etched from brass. For some of the skylights a combination of the techniques were used.   Etched parts for skylights   Boiler-room skylight The prototype construction of the boiler-room skylight is not completely clear from the drawings I had, so that I had to 'fudge' it a bit. First the central piece that supports the chimney was shaped from a piece of Plexiglas. The PROXXON drilling machine was abused as a milling machine to this end: a diamond-cut milling bit was taken up into a collet and the height of the machine set so that the bit reached just below the table. Now the Plexiglas part was passed free-hand along the mill. The form to be cut out was printed on a piece of paper that was stuck to the Plexiglas. It was tested against the shape of the etched grilles in order ensure a snug fit. The box around the skylight was constructed again from Pertinax.   Shaping a Plexiglas-core for the boiler-room skylight   The assembled boiler-room skylight   To be continued ...

And the show goes on ...
 
**************
 
The gun barrel and lock
Turning the barrel
Because there will various visible areas of bare metal, the material of the original, that is steel, was chosen.  A piece of round bar was faced, centred and rough drilled for the bore. This hole served as a protective counter bore for the tailstock centre during the following turning operations. In order to get a good finish the automatic longitudinal feed for the lathe was set up with the change gears. Unfortunately the minimum feed per revolution on the watchmaking lathe is still too high to get a 'mirror' finish. One day I have to construct some sort of reduction gear. The outer part of the barrel has a slight taper (1 degree included angle) and the top-slide was off-set accordingly for this operation.
 

Facing and centring a piece of steel rod for the gun barrel
 

Rough drilling of the gun barrel
 

Turning the barrel using the automatic fine feed
 

Taper-turning with slide rest off-set
 
For rounding off the ends of the rings the lathe’s hand tool rest came to good use. The work was finished off with fine wet-and-dry paper (remember to cover ways!) and steel wool. The bore was bored to diameter using the slide-rest and a micro-boring tool. I had originally envisaged to also show the rifling, but a quick calculation told me that for a 1 mm bore and 72 rifled fields I would need a tool edge tha is just over 0.04 mm wide ...
 

Rounding the 'rings' using a hand turning rest
 

Boring the barrel using a micro boring tool
 
To be continued ...