Vosper 73' Type II - Motor Torpedo Boat - MTB523

Photo courtesy of the UK Imperial War Museum https://www.iwm.org.uk

I am working on a 20th scale model of the British Vosper 73' version II boat, this is based on drawings of MTB 523 obtained for me by one of my cousins who worked there.

The Vosper boats were built in the Vospers Yard in Portchester in my home town of Portsmouth England.

MTB523 was a late war production and I don't believe it saw any action. The type II was an upgraded 73 footer fitted with an Oerlikon 20mm astern, a British 6 pounder canon replaced it on the bow, two twin .303 Vickers machine guns, one to port and one to stbd and two 18" torpedo tubes mounted further aft towards the stern than the type 1 boats. These boats were powered by three USA built V12 Packard engines.

The Vosper 73' boat hull, type 1 and type II were both very similar, with the type II fitting a 6 pounder gun on the bow, losing two torpedo tubes and moving the oerlikon canon to the stern. These hull's were a relatively flat planing hull but with a rounded keel from about rib 10 onwards, widening out to a larger and larger radii and then tapering off to an absolutely flat bottom at the transom (stern). Other than the rounded keel the bottom tunnel shape is quite similar, in some ways, to the U.S. Higgins hulls, in fact the later Higgins hull removed the slight tunnel effect at the transom, later in the war, and also ended up with an absolutely flat bottom at the transom, the same as the Vosper to apparently improve it's handling.

m

For a much larger version click on the picture above or here.

For a much larger version click on the picture above or here.

I have re-drawn the above drawings in Autocad to try to match the poor quality printed copies that were from Vospers, some of the text was near impossible to read so I apologise in advance for any errors and in some cases there are xxxx's where the text cannot be made out. I have also replaced the engine box like drawings with my previously drawn Packard images, the remainder is drawn as faithfully as I can.

From these re-drawn drawings I have developed the "lines", which are slices through the hull at set intervals from the centerline and the bottom of the keel.

The "lines" - this is my interpretation at 20th scale.

If you click on the picture above you can get a much larger image or click here.

P.1023 - Notice the 6 pounder cannon has been removed.

For a much larger version click on the picture above or here.

P.1032 - Notice the torpedo tubes have been removed but the base is still present.

For a much larger version click on the picture above or here.