Seamanship and ship handling in the age of sail.

Seamanship and ship handling in the age of sail.

I have started this thread to record the results of my research into this subject over the past few months.

The research began as a result of a discussion over the way that sailing vessels turn. The original premis being that because 18th century warships were large and heavy they must have turned slowly and through a wide arc (similar to modern day super-tankers). My own limited experience of sailing did not support this theory, in my experience sailing ships handle much differently to power-driven vessels, if only because they are sucked through the water rather than being pushed and thus have the ability to use their sails to enhance their rate of turn rather than their rudders.

However, this started a debate which motivated me to seek further information on how tall ships change direction under sail, plus a clearer understanding of how rapidly such changes of course could have been achieved and over what distance in terms of turning circles etc.

Scope of my research to date.

My first port of call (forgive the pun) was the Cruizers Forum. Which is a discussion board frequently by the masters and owners of modern day tall ships. Here I posed the question of the manoeuvrability of tall ships to those who still sail them.

I expected to get quite a quick answer and rapid enlightenment from people who after all did it every day. But it proved less straight-forward.

The basic response came down to 'it depends'.

And what it depends on is a wide range of different things including:

- Wind and Sea State: Certain wind strengths preclude certain methods of turning, as do certain sea states. Trying some manoeuvres in the wrong conditions can literal pull the masts out of a ship ("spring the sticks" - in naval parlence). Whilst others simply won't work under certain conditions. This is particularly true of 'Tacking', which seems to have quite a small window of viability in terms of wind strength and vessel impetus.

- The vessels speed prior to the start of the manoeuvre: Some manoeuvres particularly 'Tacking' rely heavily on the impetus of the ships speed through the water prior to the start of the manoeuvre to carry it through the turn. This is particularly true of manoeuvres like 'Tacking' which carry the bow of the ship through the wind and therefore denies the ship any assistance from it's sails for several vital minutes.

- Seamanship: Probably the most important factor of all seems to be seamanship, both of the ships master and officers, and of her crew. The process of turning ship requires the careful co-ordination of a wide range of operations in sail handling, and a certain amount of judgement and experience in their timing. If the master and/or crew don't know how to perform these manoeuvres, or don;t have the expereince to judge when to do them correctly then the manoeuvre is either impossible, or doomed to failure. Thus some ships can perform it, whilst others can't.

- Ship design and ship state: Some ships are more capable of performing some manoeuvres than others, simply because of the way they were built, rigged, or designed, or because of the state of their hulls and rigging at that particular time. A ship which has been at sea for a long while will be naturally slow to manoeuvre due to the fouling of it's hull, making any turn reliant upon it's impetus more likely to fail. Likewise, a ship on shortened sail, or with its rigging damaged or taken down in battle has it's options severaly reduced when changing course.

So, whilst the question appeared simple the answers weren't.

However, I did get sent some very useful video footage of tall ships changing course particularly from the San Diego Maritime Museum. I was particularly embarrassed to find that the San Diego Maritime Museum has such an active sailing research department, including the use of the full size replica of HMS Surprise from the film 'Master and Commander', when all the British Maritime Museum seem to have are models and plans. What a sad reflection on Britain's maritime heretage, Nelson must be turning in his grave.:disgust:

[Anyway rant mode off, and back to business]

What I did obtain was a number of book references, which I was assured would explain to a 'land-lubber' like me how tall ships work. Armed with this list I descended on my local library, where I was told that all of the books on the list were extremely rare and not in the libraries collection. I therefore, tried Ebay and quickly discovered that they are also extremely sought after and therefore, expensive (e.g. £30-£60 each :whistling).

In the end I did some careful research and chose the three most promising books on the list and returned to the library to ask if they could order them in from other collections. This wasa chargeable service but much cheaper than buying the books.

The books I ordered were:

"Ships and Seamen of the American Revolution" by Jack Coggins ISBN 0-486-42072-8 a copy of which was tracked down in the Aberdeen University Library.

"The Seamans Friend" by Richard Henry Dana ISBN 0-356-047628 a copy of which was found in the Humberside Library.

And a beautifully illustrated book called "Seamanship in the Age of Sail" by John Harland ISBN 0-85177-179-3 which came from Great Baddow Library in Essex.

These books have arrived and what I hope to do in this thread is summarise the wealth of information they contain, together with the insight provided by the masters of the Cruizers forum into a resource which will be of value to modders and other with an interest in hisotrical ship handling in the 18th and early 19th century.

It's obviously going to take time to go through and summarize the information I have to hand and so I've put some placeholders down which i shall fill in as fast as I can alongside my other projects. In another thread, I am also extracting the names of all the ships that served in the American Revolutionary Navies for the benefit of those who like to give their ships accurate names.

If any readers sail or have other references then please chip in with your own observations etc.

Part 1: A Question of Balance

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Part 2: Tacking and similar manoeuvres

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Part 3: Wearing Ship and the Jibe

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Part 4: Rigs, sails and rigging

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Part 5: External factors and their impact on ship handling.

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Part 6: Enemy In Sight! - The experience of combat in the Age of Sail

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Any plans on continuing in this Didz? While game engine is not exactly correct in depicting this (especially the way ships turn) its quite hard for somebody without any experience with sailing ships to create a realistic sailing model for ETW/NTW.. your first post is very helpful in that.

I've begin a thread about European navies here : http://www.twcenter.net/forums/showt...VIIIth-century (Evolution of European navies and ships through the XVIIIth century)
Mabe some informations could be added here ?

If you guys are interested in reading the results of my research, then I'll try and find the time to complete this article. I had a hard drive crash which put a stop to my work for a while, and I've since landed a major contract which has kept me busy thirteen hours a day since last November 2011, but I should still have the raw research material on my rescue disk and this programme is due to launch by the end of the month. So, I'll try and pull it together and publish it above.

THanks Didz

Am I being too selfish to beg Didz to finish this...:whistling

My first reflection is that top sails should improve not only top speed but also maneuverability,
based on @Didz commentary.

First you have the 'Tacking' rely heavily on the impetus of the ships speed through the water prior to the start of the manoeuvre to carry it through the turn,
and secondly you will also get added thrust to compensate the energy bleed in a turn.

The copper bottom etc would also result in better maneuverability due to less friction and as such less bleed,
on top of the already higher starting speed at the beginning of the turn.

The momentum of a heavy ship would make itself known,
but the truth is that it is the proportion between sail area and ship weight,
no different than wing load on an aircraft.

So a heavy ship could have a sail load lower than a small ship if only you make the sails large enough,
and thus be more maneuverable.

If you have the values of both sail area and ship weight, you can get a rough idea on how comparatively maneuverable they are.

There is one exception to this when comparing sail ships and aircraft,
namely that a sail ship lose thrust altogether when wind is not propelling it,
so here weight/momentum becomes the sole issue, together with initial speed / tacking