British WW1 Tanks

[MartinWills]

I have been giving some thought to the transportation of tanks and not come to any firm conclusions, even from consulting various volumes on the subject.

I know that railway loading gauges dictated that sponsons needed to be demounted for transportation by rail. Tanks were transported on railway wagons specially made for the purpose.

I believe that male tanks had to have the sponsons fully demounted. The gap left would be sheeted over with tarpaulin or wooden sheet. Presumably the sponsons were carried separately either on the same wagon or an adjacent one in the train, but how were they mounted on the wagons for this purpose and were the 6lb guns dismounted as well.

As for female tanks I believe that there were two options. One was to swing the sponsons inboard, though I don't know exactly how this was done. Alternatively the same approach as for male tanks could be adopted, but again how were the sponsons mounted on the wagons.

Finally, for Mk I tanks, were the rear wheels left in place for rail transport or not?

Depending upon whether I can bottom out these questions I am contemplating building a small model diorama around a tank loading or off-loading point and I know I have the option of Mk I male; Mk. IV female and Mk. IV male verions of the British Gt. War Tank.

I know if all else fails I can raise a query with Bovington, but somewhere on the forum they may be someone who has all the answers.

Thanks

Martin

[Robert Dunlop]

Mitchell wrote the following in 'Tank Warfare: The story of the tanks of the Great War':

'In those early days (pre-Mark IV) the difficulties of entraining were great, and each sponson had to be unbolted and hoisted by means of a girder and tackle onto a separate trolley, as otherwise the machines would be too wide to travel by rail. Every sponson with its gun, weighed 35 cwt...' I would guess the same technique was used to put the sponson back on.

The male Mk IV sponson was unbolted and then manhandled into the interior of the tank. There were rings on the sponson which had to be aligned with rings on the engine plate, then pins were inserted. Sometimes, other tanks were used to push the sponson in if it had become distorted.

[Robert Dunlop]

The shortened naval 6 pdr of the Mk IVs did not have to be dismounted when the sponson was slid in. I don't know for the early Mks.

The photographs of entrained tanks often show them completely covered in sheets. This was especially true for the early Mk 1s, when secrecy was crucial. There are no sponsons in the one photograph that I have that shows the full length of train with tanks. Similarly, the photograph of covered tanks on a cross-channel ferry does not show sponsons. I think the wheels will have been transported separately as well.

[MartinWills]

Robert,

Thanks for this - it's a start in the right direction.

I have a suspicion that the Mk IV (and later) females may have crept just inside the continental loading gauge and may have been transported with sponsons in place.

Thanks again.

[Robert Dunlop]

I believe that is correct. I have several photographs of female Mk IVs with sponsons on train transports. The MGs have been removed and their portals covered.

For Cambrai, the tanks were transported without sheets. Partly, this was because of the fascines that were loaded onto the tanks before entrainment. I suspect it was no longer considered important anyway.

When the male tanks were being transported, the sponsons projected out from the edge of the tank, about as far as the sponsons on the female.

[Terry_Reeves]

Martin

Henniker's "Transportation on the Western Front" pp 305-313 deals specifically with transportation of tanks by train. Although it will not answer all your questions, it covers loading and unloading, and the introduction of tank ramp wagons in this respect. Also included, is the introduction (1917) of "Rectanks", standing for Railway Executive Committee's tank trucks. These were special wagons capable of carrying a 40 ton load. The problem of sponsons is also mentioned, particularly with regard to the passage of trains over bridges.

The book is part of the Official History series.

Terry Reeves

[MartinWills]

Terry,

Thanks for this pointer - obvious really - I should have looked there.

When discussing one particular move of tanks in May 1917 (2nd Brigade, Heavy Branch) totalling 72 tanks plus 12 supply tanks enough information is given to deduce that the 72 tanks were transported with sponsons whereas the two trains carrying the supply tanks (presumably older Mk. I or Mk. II types) each carried six tank wagons plus 3 20 ton flats for sponsons (i.e. four sponsons per flat). I note that the officers had a coach and the ORs had covered wagons, as per usual.

Henniker says that the early sponsons weighed around 3 - 4 tons, and that the early tanks weighed 28 tons, another type weighing only 15 tons. I wonder if the latter was the boilerplate MkII originally intended for training. By 1918 the various types apparently weighd in from 27 to 40 tons.

The origin of Rectanks is an interesting debate. Although Henniker credits the Great Western Railway with the initial ones in December 1916 I believe that The London and North Eastern Railway (serving Lincoln?) was reponsible for the initial build of rectanks. Henniker talks about the problems of end loading. Interestingly it was found necessary to fit the end of the rectanks with "screwdown" jacks for stability. There is a discourse on this in Atkins, Hyde, Tourret and Beard's volumes which covers GWR Rectanks and others. There was a small ramp rising towards the end of each wagon for the last foot or two of it's length.

Robert's comments about fascines is interesting - I have seen pictures of tanks on transporters with fascines but I am moved to suggest that these were not transported any great distance as I suspect they would not have gone under most railway bridges.

Thanks again for your pointers.

Martin

[Robert Dunlop]

I have seen pictures of tanks on transporters with fascines but I am moved to suggest that these were not transported any great distance as I suspect they would not have gone under most railway bridges.

An excellent point. One of the photos is labelled 'Double-headed tank trains prepare to move out from the Plateau railhead to carry the tanks, complete with their fascines, to the forward unloading points. I don't know how far the Plateau railhead was from the forward unloading points.