Saturday, 20 February 2016

Simulating gunfire in naval wargames: Fred Jane and Fletcher Pratt

The following photograph of a Fletcher Pratt Naval War Game in progress surfaced very recently on Facebook.


When I saw it I was struck by several things. Firstly that nearly 50% of the participants were women; secondly that they all seem to have deployed their destroyers between the two battle lines; and thirdly that at the distance on the floor at which they were estimating the range between their own ships and their targets was very short indeed

Of these points the first is easily explained. By 1938 taking port in one of Fletcher Pratt's games had become a social event, and both men and women took part in quite significant numbers. Amongst the latter was Inga, Pratt's wife, who ran wargames during her husband's wartime service in the United States Navy, and the former included Isaac Asimov, L Ron Hubbard, L Sprague de Camp, Trevor N Dupuy, and Jack Coggins.

The second point I find less easy to explain. It has always been my understanding that once the battle lines had formed up and begun firing at each other, smaller vessels kept well out of the way until they could be deployed to administer the coup de grace on crippled enemy ships. In this game they seem to be being used to try to disrupt their opponent's battle lines during the slogging match between the opposing battleships, and may well be the result of one of Fletcher Pratt's experimental tactical exercises.

The third point is the most difficult to explain. Having taken part in quite a few naval wargames over the years using Fletcher Pratt's rules, I know that the estimation of range is quite difficult. It is my experience that players who are new to the rules vastly underestimate the distances between the models, and so end up trying to get as close as possible to reduce the level of error in their estimations, whereas once more experienced players have 'got the range' they tend to try to keep any changes relatively manageable so that they can keep hitting the enemy. In this case both sides seem to have shortened range and in theory should be hitting each other with almost every shot they fire. (I say 'in theory' because in the excitement of battle I have known players to mistakenly increase their range estimations when they should decrease them and vice versa.)

What I find interesting is the method that Fletcher Pratt adopted for simulating gunfire in his naval wargame, especially when it is compared with that used in the earlier but equally famous Fred Jane Naval War Game. In Fred Jane's game players had to try to hit a paper target with something that looked like a wooden fly-swat (known as a 'striker'), in the face of which was embedded a small pinhead. The pinheads were not in the centre of the head of the strikers, but offset ... and players were not allowed to look at the the face of the striker before they used it.

Examples of the equipment used to fight a Fred Jane Naval War Game. Included are two wooden strikers, one of the 1:3000th-scale models used, a target, and a scorer (i.e. an image of the target ship on which any hits are recorded).
In addition the size of the target they had to hit varied depending upon the range.

A reproduction of a target. The smallest was used when the range was 4,000 yards, the middle-sized target when the range was 3,000 yards, and the largest when the range was 2,000 yards. The ship represented here is the Turkish battleship Torgud Reis.
Fred Jane's method was developed when battle ranges were expected to be short, and when individual gunlayers were expected to use sighting telescopes to aim their guns themselves. At the time Sir Percy Scott was at the forefront of the improvement of British naval gunnery, and one of his training methods was the use of the 'Dotter'. It was developed and used as follows:
Fortunately it occurred to me that I could design a contrivance with a target moving up and down at about the same rate as a ship rolls, and compel the pointer to manipulate his elevating wheel quick enough to follow it. This contrivance was made, and the men christened it the 'Dotter'. A description of the arrangement may be of interest.

On a vertical board, opposite to the muzzle of the gun, was a metal frame which, by means of rollers and a handle, could be moved up and down at either a slow or a fast rate. On this frame was painted a bull's-eye, and beside it was a card with a line drawn upon it. On the face of the board, and moved either up or down by the muzzle of the gun, was a carrier containing a pencil. When the men under instruction pressed the trigger of the gun the pencil, actuated by an electrical contrivance, made a dot on the card, and the pencil at the same time moved a space to the right. If the gun was truly pointed at the bull's eye at the moment of firing, the dot would be in line with the bull's-eye. If the gun was not truly pointed, the amount of error was indicated on the card.

At this machine the men were given constant practice, and in a very short time they were able to follow the target up and down with remarkable accuracy. In other words they had all learned to do what the one man had done intuitively.

The next time we went out firing there was a considerable roll, but it made no difference to the men, whose shooting was admirable, a fact which I attribute entirely to their course of instruction at the 'Dotter'.
FIFTY YEARS IN THE ROYAL NAVY by Admiral Sir Percy Scott,
BT., K.C.B., K.C.V.O., HON. LL.D. CAM (Published 1919)

A 'Dotter' in use.
A 'Dotter' being used in combination with a deflection teacher. This was also developed by Sir Percy Scott.
When compared with Sir Percy Scott's 'Dotter', Fred Jane's method of simulating naval gunfire seems to be quite a reasonable analogue of it.

During the period after the Russo-Japanese War the world's major navies began to experiment with coincidence and stereoscopic rangefinders in place of sighting telescopes. Alongside these came director control of a ship's armament, where all the guns were controlled centrally by the gunnery officer rather than by individual gun captains, and the introduction of electro-mechanical gunnery computers such as the Dreyer Fire Control Table which enabled director controlled naval guns to attained even greater accuracy.

The Scott Director Tower.
A 1918 Mk.V Dreyer Fire Control Table.
Fletcher Pratt's method of simulating naval gunfire seems to have been developed with these changes in mind. Players sight their guns as if they were all firing a single salvo in unison at the same target, estimate the range, and write orders on the firing arrows they have placed down. In an earlier version of the rules the players could stipulate where the shells landed (e.g. 'All shells will land on the same spot at x-inches range' or 'Shells will land x-inches apart, starting at a range of y-inches'), but in the later version it was assumed that two shells from a salvo would fall at the range written on the firing arrow, with each additional shell in the salvo alternately falling one inch short or over (i.e. in a salvo of eight shells, two would fall at the given range, three would be under at distances of one, two, and three-inches respectively, and three would overshoot by distances of one, two, and three-inches respectively).

The Fletcher Pratt system in action. The red golf tee indicates a hit whilst the blue tees indicate the fall of shot of misses.
This certainly seems to reflect the results of live gunnery fire exercises that took place between the wars, and as such it must also be regarded as a reasonable analogue.

The only problem with both the Jane and the Pratt methods is the time it takes to adjudicate the results. In Fred Jane's gunnery rules mechanism the umpire has to carefully examine the target and then transfer the results over to the scorer. It has the big advantage that the firer has no idea what the results of their gunnery are, but once squadrons of more than three or four ships per side are involved, the process can become tediously slow. In the the Pratt rules it requires two umpires to adjudicate the fall of shot (i.e. one at each end of the tape measure, with one making sure that the tape lines up with the firing arrows and the other placing the fall of shot markers) and sometimes a third to mark up each ship's record card. The damaged caused is secret from the firer, but as they can see where their fall of shot markers actually land they can use that information to adjust the aim and range estimation for the next turn.

The photo of the pieces used to play the Fred Jane Naval War Game comes from the collection of Curator Branch, Naval History and Heritage Command.

14 comments:

  1. Another explanation of the 'third point' is that the photographer asked for the ships and players to be moved close together to get them in the shot.

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  2. Ncc1717,

    That is distinctly possible as I think that the picture may originally have come from an article LIFE magazine did about Fletcher Pratt's wargames. It might well have been one of the first times a staged shot of a wargame was taken.

    All the best,

    Bob

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  3. Fascinating stuff! Jane's method for resolving gunfire is really quite ingenious.
    Instead of standing on their heads to determine LOS and divine range, these participants would have found a laser pointer quite a useful tool.

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  4. Jonathan Freitag,

    Jane's system works very well ... but it is very time consuming.

    I have given serious consideration to buying a laser tape measure for exactly the reasons you state ... and may well do so if I ever decide to stage a large naval battle using Fletcher Pratt's rules at some time in the future.

    All the best,

    Bob

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  5. I agree that this is fascinating. Especially the parts about the fire tables. Unfortunately, I have the mathematical ability of a nasturtium. I stare at the description of this like a cat trying to puzzle out sudoku before diving for cover into a cool dark recess. I am full of admiration for the people who are able to devise these things.

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  6. Stephen Briddon,

    The fire tables were - in their time - at the forefront of technology. By the Second World War they were able to process all manner of data (e.g. the firing and target ships' speed and heading, weather conditions etc.) and transmit to the gunnery control officer and the gun turrets the necessary bearing and elevation data required to hit the target. When input from radar was added, the accuracy of naval gunnery improved exponentially.

    All the best,

    Bob

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  7. Thanks for posting this, I've been trying in vain to find any reference to that "paddle method" for naval gunnery. A variation I saw had a needle off center of a disc that was on the end of a stick with the disc mounted like a wheel on an axle. The idea was the player would have a harder time figuring out where the needle was because any rotation moved it.
    So glad to know the names to Google now!

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  8. A nice find and sounds like an interesting article, another piece in the history of wargaming jigsaw.

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  9. Mr. Pavone,

    Before I found this photograph I had never seem an image of an actual 'striker' before, although I had seen a line drawing of one. The photo gives you some idea how big it was, whereas the drawing did not.

    Adding a rotating head to a 'striker' sounds as if it would add a whole extra level of unnecessary complication!

    All the best,

    Bob

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  10. Brian Carrick,

    We are so used to developing analogue devices today that we often forget that our predecessors were quite capable of doing the same. These two methods are a case in point, and reflect the levels of technology that were available to them at the time.

    All the best,

    Bob

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  11. One of my first wargaming friends, Arnold Hendrick, designed a variant of Fletcher Pratts rules, wherein, amoung other differences, one had to move his ship, place his fire arrow, estimate and write down the range all within 30 seconds! It managed to cause some blue-on-blue casualties as well as all other kinds of realistic mistakes. We played on of these in a large parking lot wherein players need binoculars and the ranges were to scale, necessitating an estimate in yards, feet and inches. a large (2-3" burst circle was allowed but very few hits (as in real life) occurred except the destroyers did some damage with torpedoes. I wish I could find the photos from then (1968-1970)>

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  12. Dick Bryant,

    That sounds like quite some battle! My experience of using Fletcher Pratt's rules on a large floor or open space is that it enhances the game considerably as players are much better at accurately estimating the distances that are between 12 inches and 15 inches than they are if the distances are 12 feet to 15 feet.

    I like the idea of restricting the time players have to move, aim, and estimate ... although 30 seconds does sound a bit draconian!

    All the best,

    Bob

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  13. Very interesting article Bob. Thank you.

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  14. Whiskers,

    Thanks for your kind comment.

    All the best,

    Bob

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