Gun Ports

[shipman]

I'm curious; was there a set convention regulating the size of gun ports relating to different size guns carried on different rated ships (ie. does a 12 pound gun have a smaller port compared to that of a 32 pounder) ? Common sense tells me there must be differences, but what are they?

Edited March 28, 2018 by shipman
Fergot to request reply referals

[trippwj]

1 hour ago, shipman said:

I'm curious; was there a set convention regulating the size of gun ports relating to different size guns carried on different rated ships (ie. does a 12 pound gun have a smaller port compared to that of a 32 pounder) ? Common sense tells me there must be differences, but what are they?

Any particular time period?  By the early 18th century there was some attempt to have a standard size, but it wasn't until later in the century that it was adopted in the yards.  See, for example, Sutherland's various editions as well as the various establishments (Compiled in book form by Allan Yedlinsky) where the port size is related to number of guns  and deck (which, approximately, matches the size of the ordinance).  There is also some guidance in various treatises published during the 1750's and later (Rees, Steele, others).

 

 

[shipman]

Came across this relevant info in my library today.

The Ship Model Builders Assistant by Charles Davis. Pages 229 and 230. States that port dimensions are indeed related to gun calibre/diameter (c1750). He also includes American Navy gun ports (c1850), which are somewhat larger. Also included is a formula to calculate the diameter of shot from its weight. Useful stuff, I hope.

[lmagna]

1 hour ago, shipman said:

Useful stuff, I hope.

 

I also have the book and the only thing that makes me wonder is why Davis didn't just state the sizes in relation to the shot size rather than just giving the formula? I'm just being lazy i suppose.

 

You need to consider Wayne's information as well though. Sometimes, like in converting a merchant ship to carry guns the ship would be too small to have the ideal ports for the size of gun or number of guns that were intended. I suppose that could apply to warships as well.

 

Lou

Edited April 17, 2018 by lmagna

[shipman]

Hi Lou,

Davis no doubt was quoting some original source, I can only assume some Admiralty dictat. But I imagine that's a good rule of thumb for 'new build' ships as we can get now.

As for wanting a simpler formula, remember things were done very differently back then.

I accept there must have been considerable variations, especially  when ships were adapted from their original use and/or when guns were uprated or down-rated.

I do enjoy these opportunities for debate on the forum. Thank you for your welcome contribution. That's why I try to broaden my outlook on these subjects and sometimes ask challenging questions. At no time have I any wish to be abrasive or rude to anyone. It's a joy to be here.

[lmagna]

No problem shipman. For the most part my comments are just that, comments. I am neither a scholar nor a naval expert and as such calling any statements by me a contribution is possibly stretching things somewhat.

 

Having said that, what I was saying about Davis offering the formula for use with out just stating the formula results especially on page 229 was just my way of saying I am being lazy. He did give the results on page 230 for later era ships.

 

All formulas like Davis used would have been the standard for designing a ship and one would think they would be considered the ideal resulting hopefully in a balanced ship that was matched to it's armament. I am sure that exceptions were made to compensate for real life considerations, or local beliefs. Shipbuilding was not just a trade but a skill back then, much like model ship building is to us today. and each master builder very probably had his own idea to a certain extent what was right.

 

Lou

[mtaylor]

I'm not sure why he gave a formula as tables for shot size, throw weight, etc. was/is available in table form.  It gets a bit murky when "length" of an inch or foot changed however. Even murkier on the cannons themselves as every country had their own ideas on how a barrel should "look".  Plus, barrel lengths even for the same shot size varied depending on the intended ship.

[trippwj]

Davis did some good work as one of the early naval architects turned hobby modeller mentor.  Writing for a much different audience, he frequently provides a snippet of the information - just enough (often) to achieve something, but not enough to go any further.  Nothing mean or lazy, just vastly different times. 

 

If we take a gander at works by Lee (masting and rigging), among others, we can quickly begin to wander the rabbit hole.  In an effort to simplify and condense large tables of numbers for lines, poles, spars, blocks, yada yada, the desired dimension (let's use the length of the mizzen gizzard on a 1730 54 gun ship (a ficticious item as I am to lazy to get my book).  The gizzard, in contemporary literature, is given as a table of length on deck (across the top) and number of guns (down the side).  Now, Lee may have gone through this and found that in 1730, the mizzen gizzard was actually 2.31 times some other item dimension, likewise calculated from some other dimension.  The thing of it is, decimal math wasn't in common use - the division left a remainder in xx/yy.  Thr builder of old would have used something like 2 and 29/94 units.  Modern calculators make those conversions to decimal so easy!