Chasseur

Yet another master class Michael

Bob Polly Agatha was my inspiration This shot particulary.
 
Michael

I really like the look of this installation with the box!  Might I suggest that you consider making another set of those cowl vents to wear as cuff-links?. 
 
I'm sure it's a variation I simply have never seen here in the US, but I've never seen two half-cowls mounted together. It makes sense if one wants the same air flow as would be realized from one whole cowl, though, obviously.  What seems to have been common here was simply the half-cowl on each side, or even more commonly, a "clamshell" cowl on each side. The "clamshell" cowl was the same as the half-cowl, except that it had no base and just the top section alone (which was sometimes shaped a bit flatter.) There was simply a hole cut in the cabin side to accommodate the air intake on the side mount half-cowls and clamshell ventilators I've seen here in the US. I've never seen a Dorade box on a half cowl, though. These side mounted cowls seem to have been far more common on early power yachts than on sailing vessels. I'm not saying there's anything improper about the pictured installation, but only that in my experience (which includes working in a classic yacht brokerage decades ago,) we didn't seem to have similar arrangements here in America. That said, as the long-time owner of a Giles Vertue sloop, I can attest that there are many such ingenious fittings which are decidedly "British" and yet rarely seen in the US. Cruciform cleats and Highfield levers are prime examples of "better mousetraps" that inexplicably never made it across the pond very often.

Actually, cowl ventilators on smaller craft (as opposed to large ships) were never intended to be shipped except at anchor or in a berth in port. They weren't for use when exposed to rain, spray, and breaking waves. (And they always posed the hazard of a loose sheet taking a flying half-hitch around one on a tack.) They had plates which screwed into the base mount when the cowl was stowed. The Dorade box was actually something of a compromise. (The loss of air flow through the drainage holes is minimal.) I don't believe they were intended for use in really heavy weather, either. Below, Dorade was relatively Spartan and dark, giving something of a claustrophobic experience. She was designed as a "ocean racing machine" in which speed was paramount and cruising accommodations secondary. (Although, at the time, standards being what they were, she is finished quite nicely, unlike today's bare-bones "racing machines.") When sailing, particularly in warm weather, it was found that there was a great need for ventilation below decks. The "boxes" permitted the cowl ventilators to be shipped in all but really heavy weather and carried their closing plates for use when needed.
 
(If anybody's wondering, my limited familiarity with Dorade was the result of having the good fortune to have a friend who had her under charter for a time many years ago.)

Great ideas and technique Michael,  the support for the saw blade is one that I will definitely file away.
 
cheers
 
Pat

I'm surprised you didn't have "Masting and Rigging," and everything else Underhill has written. They are encyclopedic in scope and detail and, as Welfalk says, "one of the Bibles." You might also consider, if you don't have them already,

https://www.amazon.com/Gaff-Rig-John-Leather/dp/B00RDCFUJO
 
There's also a Second Edition written thirty years later with some added material,

https://www.amazon.com/Gaff-Rig-Handbook-Techniques-Developments/dp/0937822671
 
and
 

 
https://www.amazon.com/Pilot-Cutters-Under-Sail-Pilotage/dp/1848321546/ref=pd_sim_14_2/135-1756572-5309355?_encoding=UTF8&pd_rd_i=1848321546&pd_rd_r=96476c2c-1308-11e9-94cc-233ded4a07d6&pd_rd_w=4UMc8&pd_rd_wg=ChJAF&pf_rd_p=18bb0b78-4200-49b9-ac91-f141d61a1780&pf_rd_r=S2GQYZV5MCQ02DN5HPWA&psc=1&refRID=S2GQYZV5MCQ02DN5HPWA
 
Cunliffe's book is fairly new, coming out in 2013. He wrote the two volume set, Pilot Schooners, the definitive tome on American and British pilot schooners and brigs. I'd love to have them, but they are decidedly pricey, so I'll have to wait until I have a sufficiently motivating excuse to buy them!  Cunliffe's Pilot Cutters Under Sail , which is in somewhat different format from Pilot Schooners, was to be the third volume in the "Pilot" set, but he lost his publisher and it took some time to find another one. Pilot Cutters addresses the English pilot cutters in great detail.  I don't have any of Cunliffe's books, but have seen the schooner and brig volumes and presume from the "preview" on Amazon that the cutter volume is every bit as encompassing and wonderful. Regrettably, they aren't cheap, or weren't when they came out. Perhaps there are some less expensive used volumes round and about now.

This should give me some Ideas. l received this in the post today.
 

 
I know I only have one mast but this will expand my knowledge.
 
Michael

I have seen this arrangement before, but didn’t know that name. I can see very well spray being kept out, albeit at a reduced efficiency of the ventilator due to some air bleeding out of the drainage holes. However, a serious wave would flood the hole system anyway.

Well, yes and no. Just to put a finer point on it, the ventilator cowl was around long before Stephens designed Dorade. What was added to Dorade was a box, properly called a "Dorade box," upon which the ventilator cowl is mounted. The box has a hole on the top for the ventilator, a half-height baffle in the middle, and a hole offset on the other side of the baffle. This permits water to enter the cowl vent, run down into the box on one side of the baffle and out drain holes, while permitting the air to move over the baffle and down the hole through the deck on the other side of the baffle.
 
The boxes weren't original to Sephens' Dorade design. They were added shortly after her launch to solve the problem of water running into the accommodation below. "Boxes like on Dorade" became "Dorade boxes," and, it seems, over the years, many have come to incorrectly call ordinary cowl vents "Dorade boxes," but the cowl vents preceded the boxes by quite some time.
 
 

Dorade's boxes on a model of her.
 

Michael,
 
You really have an eye for details!
I am learning with every post of you.

First a happy new year to one and all. Thanks to all who have visited and pushed the like button.
A tiny bit (no pun intended) of an update. Drilling the mounting holes in the dorade vents with a .020" drill bit.
 

 

 
Next I needed to sort some pins, the reason they need to be sorted is because the heads are stamped and some are really out of whack.
 

 
You can really see the difference in the next picture.
 

 
Then once the heads were chosen for size a second sort was done by setting up a test for concentricity. this was a simple roll test and if it rolled a good distance then it was OK.

 

 
Next the were set up in the small pin vice in the lathe and filed down to about half the head size, I didn't measure this but it is around .031" they were rounded polished and then a slot put in to create faux round head screws, which are actually pins that will hold the Dorade vents to the cabin sides.

 
Test fitting the "screw" in the vent next to a "standard" pin
 

 
That's it for now. 
 
michael

Saw today in the National (Scottish newspaper) that there's a contract to bring Falls of Clyde home to the Clyde to be refurbished and sent to sea as a green cargo carrier, sail training vessel, plastic collection and processing plant..... There's hope for her after all. :)
 
 

Interesting design and mechanically quite complex for something installed on the deck of a ship. The design seems to be somehow inspired by the steam-pump design for fire-engines, which had to be very compact. The cross-head there slides in frame perpendicular to the piston rod. I wondering whether the elaborate cams drive two-stage pumps: suction pumps become very ineffective say above 7 m or so; by dividing the height over which the water is to be lifted into two stages, you can achieve greater lifting heights. The cams would help timing the movements of the pistons. Just some wild ideas ...

Well solved, Gerald! Victorian engineering was impressive; the railway engines and items such as Babbage's test portion of his Difference Engine. Then the Holtzapfel engraving machines as well.

Fig-148 After some experimentation with the cardboard cut out and drawing pins as pivot points, I eventually got the gist of what it was all about, and actually made a card board model of the mechanism that would move the connecting rod vertically up and down, with no sideways movement at all.  The next question was how to make it in metal, as this was precision engineering to a very high order, in fact so high that I needed a CNC machine to solve the problems - which begs the question how did they make this in 1878 - I still do not have the answer to that one.  Perhaps when we see the complete mechanism working, some one will come up with an answer to that one as well.

Fig-145 The Bilge Pumps shown here are those of the Star of India, and are typical of all that I have ever seen and photographed, note that the elongated shape of the two pumps is fore and aft, which again is typical of those fitted to the Windjammers of the late 1800s.  Note also that there are just two pistons or rather pumps on a single crankshaft and that probably forged in the blacksmiths shop.  If so made, it would have been very difficult to forge it to take 4 pumps in the restrictive space between the Fife Rails and between the mast and the deck house that is the usual location of the Bilge Pumps.  In later times, the pumps were made as double acting, but at this date I do not think that it was so.
 
The Falls of Clyde was the first of the Falls Line fleet of iron four masted ships and barques built on the Clyde, and this just three years after the very first of the new breed, this being the County of Peebles, so we are in a period of innovation , a new concept of ship design to compete with the ever advancing Steam Ship. So we can expect the pumps to be of advanced design, and indeed they were.  Now began the search, luckily the original costs book for Hull-17 (Falls of Clyde) is still with us, and this lists the Bilge Pumps as manufactured and supplied by R.C. Wallace & Co with an address as Glasgow.  Further research in the Post-Office Annual Glasgow Directory for 1878/79 identified the company with an actual address, yet further research revealed two more companies associated with the pumps R.C.Wallace & Sons, and Wallace and Crawford, in fact the Wallace and the Crawford families were closely involved with each other way back in history, and that his initials R. C. stands for Robert Crawford Wallace. 

There is always hope Sailor1234567890, the latest is that she will be home in March 2019 - If you wish to help save the old lady monetarily or otherwise, drop a line to < savefallsofclyde@gmail.com > they will be pleased to hear from you - Remember she will be 140 years old on the 12th of December -too good to lose at this late hour, she must be saved and brought back to her birth place in Glasgow and not sunk as a divers wreck off Honolulu.
For those interested in my third and final model of her, I have here included a shot of progress todate - this is now being covered as the ‘Current Project’ on my web site, and may be covered here in further detail, if requested after this one finishes - it shows her as originally built from the scant details still with us.

Fig-144 A photo showing the same holes in the deck plating of the actual full size Falls of Clyde.  The Bilge Pumps were removed in 1912, when she was fitted out with internal tanks, as a sailing oil tanker, but luckily the deck plates were left intact to indicate the type of pumps originally fitted - There are no photographs of what these original pumps looked like, and until I manages to dig up the original data, with the help of the staff of the University of Glasgow Archive department, no one had any ideas about them, other than they must have been quite unusual.  I have visited almost all of the old Windjammers that still sail the seas, and a lot of those tied up as Museum ships, and in all cases, the elongated holes to take the Bilge Pumps have been positioned fore and aft, and not across the deck.  Thus stated a very interesting search - find and reconstruction - but for next month.

Fig-143 All is now complete excepting for the ships Bilge Pumps. Note the two elongated holes in the deck plating, as an indication of where they will eventually be located.

Fig-142 The completed Midship house in place with Jock the riveter there to check the scale.

November 2018
Fig-141 The midship House frame work of angle iron - brass - is first tinned then located to the individual positions, one at a time, and heated with he carbon rod to melt the soft solder to attached it in place.  Note that paper wrapped around the carbon rod to insulate it from the side of the deck house.  This was a problem in the early stages, as contact with the rod will cause it to heat up and melt anything close by.  But a small sheet of paper rapped around it and held in place with Cellotape was all that was needed to solve the problem.

For those interested in the Falls of Clyde as a subject, my third model of it - the fully detailed Water Line model, may find my web site of interest for October, it being the start of it as my ‘Current Project’ - see also ‘News & Comments’ for more details on the subject < http://www.geraldwingrove.com/Home_Page./Home_Page.html >

Fig-130  To assemble the parts, the first three rows - nine plates -  were adjusted around the Master Pattern and held in place with the aluminium rings, then heated at strategic spots to melt the tinning solder to hold them in place, sufficient to withdraw the aluminium Pattern, after which further heating with the resistance soldering unit was sufficient to completed the exercise.

Fig-129 We now come to the masts, in this case just stump masts, as I wished to show the three angle iron ribs on the inside.  Each is made up of a stepped series of three iron plate circling the mast and riveted together with a double rows of rivets, with the stiffening angle iron ribs running down the centre of each plate.  All rivets would have been countersunk to maintain a smooth surface to the out side of the masts.  To assist in their construction I machined a length of Aluminium rod to the inside diameter of the Masts, with a slight taper at each end to accomodate it where required, this then forming the Master Pattern.  The final shape and size of each mast being determined by a series of aluminium rings, machined on the inside to match the required out side diameter of that  part of the Mast.  A small block of aluminium was also machined with a groove down the centre, to match the new Master Pattern.  These then formed a male and female die, between which all of the mast plates could now be formed.  Each plate was marked out and cut to size in threes, provided with the double row of rivets down each side, annealed, then cleaned and tinned before being pressed to shape between the pair of Dies.

Fig-128 The main hatch now in place on the centre section of the model,. Later I added a leader down to the Tween Deck and on down into the Main Hold - not sure if it was originally there, but is at least a logical place to locate  one and looks natural.