Combined Masts

[BANYAN]

Hi folks.  I am just getting to the point of having to draw up and plan the spars and rigging for my HMCSS Victoria build (1855). 

 

I was getting, and remain somewhat, very confused while reading the Contract specifications, looking at the lithographs and Photograph of the ship, and the descriptions and tables in contemporary books by Fincham, Kipping and other authoritative authors such as Lees, Marquardt and Underhill.

 

Of note: during this period there was a move towards 'combined' masts (poles); and, Victoria was built to merchant standards but rigged to meet RN quality.

 

The core of the issue: 

 

Victoria was designed and built as a three-masted schooner, but Barque rigged/sail configuration.  I initially got hung up on "Barque" and all the authors discuss this rig and the usual mast configuration for this period as 'lower mast, topmast and combined top-gallant mast + royal mast (as a pole) providing excellent tables etc to allow the taper/diminishing of the masts to be calculated from the specification values.

 

HOWEVER, looking at the imagery it is obvious 'Victoria' was configured with a 'lower mast, and combined topmast, top-gallant mast and royal mast as a single pole (confirmed in the Rigging Warrant also).  Now for the delima that I hope someone may assist me with.

 

 

None of the authors offer a table, or formula that I can understand to calculate the taper/steps of the combined 3 masts to allow a realistic end size (Royal mast head), nor to calculate the step (at the stops for each mast).  The Contract provides the start diameter (at the cap) for the topmast, and the lengths of each mast (so I know where the stops are) but not how much to reduce the mast (step inwards I assume as the imagery seems to show a 'funnel' - iron and copper combo - rather than 8-sided) at these points.

 

This combination appears to be typical of three-masted schooners (merchant types at least) for this period and was introduced into the RN for later gun boats (eg Beacon class - HMS Beacon 1867) - did Victoria set a standard ?   

 

HMS Beacon moored in Malta - from Wikipedia (commons)

 QUESTION

 

Can anyone provide me with a reference/pointer to a table or formula to calculate these?

 

I have tried using the individual tables for topmast +  table for combined top-gallant and royal (from Kipping and Fincham - close but not the same) using the head size of the topmast as the starting (given) size for the pole but the result does not seem realistic (too narrow) at the head of the royal. Also, this method  does not tell me how much to step/reduce the diameter of the pole at these junctures to fit the funnels (noticeable in all the imagery).

 

Any info or guidance would be most welcome

 

cheers

 

Pat

 

p.s.   I have also not been able to locate a single drawing/illustration of this type of pole with associated fittings.

Edited March 13, 2019 by BANYAN
Added graphics and fixed text

[wefalck]

Just to say: I had a look at a couple of German textbooks on rigging, one of 1869 and one of 1903. As expected, the latter only talk about steel masts, but the former does not mention this kind of masts at all. There are, however, proportional dimensions for different steps on the mast from which one perhaps can deduct the information you need.

[rwiederrich]

Wow...Pat.  You have gone all out, as far as trying to locate and apply the math that was used to determine the mast steps.  A noteworthy endeavor, however, my particular method is to understand the stepping process and *need* in actual prototypes, and then rely on my developed acute perception ( a very good eye) for measurements and translations there of....and then give it my best shot.

 

There will always be inaccuracies in our models to some degree(None of us were there when our ships were actually built), and time can dilute the information we seek.  Unless your vessel construction is well documented and not expunged by time...you have to make certain assumptions... based on the best practices of the time.

Crothers book on masting of American clippers might be of some help.

 

Rob

[BANYAN]

Thanks Eberhard and Rob; much appreciate your time in looking into this.

 

Eberhard; you are quite correct in the tables being available and some 'deduction' may allow me to approximate something I can live with.  That is the main issue you have identified; all the books (including those about clippers) all talk about the more usual mast configuration and do not discuss this type even though common to three-masted schooners of this era.

 

Rob; a good 'eye' can't be beaten and some form of intuition supported by some guidance, will probably allow a reasonable/acceptable approximation to be made.  

 

I was just hoping to be able to offer the 'correct' tables in the associated data (spreadsheet and book) I am collating - not for publishing though; they will be made freely available.  I am hoping in that presenting my reasoning in making the decisions on fit form and function of the fittings, furniture, equipment etc of this ship, that others may value add in the future allowing a more complete picture of this ship to be generated.

 

cheers

 

Pat

[BANYAN]

Hi again all,  going back through my research materials I found an interesting (possible) link with the Arrow Class vessels (1854).  These were a very slightly smaller version of the same type of vessel, as can be seen by comparing the specifications:

HMCSS Victoria specifications:

·    Length: 166 feet (between perpendiculars).

·    Beam: 27 feet.

·    Depth of Hold: 16 feet.

·    Tonnage: 580 tons (burthen) - 880 tons by displacement.

HMS Arrow specifications:

·    Length: 160 feet (between perpendiculars).

·    Beam: 25.4 feet.

·    Depth of Hold: 13.3 feet.

·    Tonnage: 476 tons (burthen).

 

One of the items a researcher turned up for me was a 'Ship Survey Reports' book (my naming as there is none given) for HMS Arrow - the contents include.

Note the following extracts for the three masts, which all refer to a pole style mast above the lower mast, so this confirms this masting convention was used in steam screw sloops at least.  This description though better fits what Marquardt describes as a lower mast with tall pole.

 

What I  would like to determine from the listed parameters/dimensions is what is meant by:

1. 'to stops' in column for length (first set of dimensions) of Fore and Main mast for the topgallant - there would have been two stops?
2. Why different lengths  between two dates very close together - probably as a result of first sea trials but looking for alternate possibilities?
3. slightly different description in second set of dimensions

Many thanks

 

Pat

[wefalck]

It seems that the proportions between lower mast and pole where changed, lowering the point where the shrouds/stay attaches.

 

I gather there may be at least two stops on the pole, namely one where normally the lower topmast would end and then another one near the top to provide a rest for the respective stays and backstays.

 

I didn't around to do this, but I wanted to sift through my literature a bit more to see, whether one can find some more data on this kind of masting. It was very common to mast steamships as two- or three-masted topsail schooners, or as barques that had fore- and main-mast with poles.

[BANYAN]

Thanks Eberhard, that is exactly what I am seeing in Victoria (the two stops); which begs the question  which one .   Apart from a discussion in Kipping (1854) about the combined topgallant/royal as a pole, there is precious other that I can find.  Would appreciate seeing anything else you may turn up.

 

cheers

 

Pat