HMS Submarine M.1 was an innovative but ill-fated attempt to overcome the poor performance and high per-shot cost of contemporary torpedoes. The unique solution was to add a 12-inch Mark IX gun, initially intended for battleship use. The gun was to be fired at a flat trajectory on the surface, or even at periscope depth (!) through use of a simple bead gunsight. 3 of the 4 M-class vessels that were ordered were actually completed, but operational results were poor at best. To reload, the sub had to surface, and it has been reported that the Royal Navy was reluctant to risk the possibility of German replication of this concept. M1, the first in the class, did not see wartime service, and sadly was lost in a collision with a Swedish transport vessel in 1925, and was discovered again in 1999, reported in a BBC television documentary airing the next year.

The diminutive OKB Grigorov kit of this unusual boat is molded in resin (7 parts) and a photoetch sheet that incorporates the diving planes, rudder, chine strakes, propellers, and a stand for the completed kit. With so few parts, construction is easily completed in one sitting. I pre-drilled additional holes to add periscopes, aerial mast and the like, and opened up the locating holes a bit more for the brass control surfaces. You are provided with two deck guns and mounts in case of loss – the same is true of the diving planes. I used a combination of instant cure thin CA and gap filling CA to assemble the kit. The only finicky parts (for me at least) were the prop shaft support arms, which need to be bent to shape to fit the hull. I had to do a little bit of trimming with my Xuron PE cutters to establish the correct angle to mate these to the hull.

I installed the 12” gun in its fully elevated position primarily to emphasize it. The only parts I did not use were the small acorn-shaped fairings mounted on the aft face of the props, as one was short-shot in the kit. I am thinking of using a dab of white glue to replicate these.

I sprayed the entire sub with Tamiya Gray Primer after assembly, and since this was close enough to the online color profiles I found, I kept it as the base hull color. The M-class boats were also used to test hull camouflage, each boat receiving a different topside color, with M-1 painted a dark green. I brush-painted some old AeroMaster Dunkelgrun as appropriate.

I wanted to add some additional detail to the sub, as there are no masts or periscopes provided in the box. I cut a piece of 0.020” plastic rod to length and shaved the upper third of it down to represent the taper of the antenna mast. I used very small lengths of an old guitar “B” string to create the three periscopes. Rooting through my spares box, I found some excellent PE railings, cut them to length and shaped them, and added them to the casing area between the conning tower and the gun mount. I stopped short of adding the outboard railings, although OKB Grigorov molds the upright support mounting locations into the hull. I used EZ-Line to add the simple rigging, but in doing so caused the plastic antenna mast to rake forward slightly. If I can find or create one, I will eventually add the White Ensign flag for a touch of color.

I brushed on a coat of Pledge Multi-Surface as a gloss coat, scrounged a very small “M” and “1” decal from the spares box, and shot a coat of Alclad Clear Flat lacquer over the completed sub (which, by the way, is all of about 4” LOA when complete). A few minutes in the wood shop yielded a suitably sized base, and voila, finished.

My thanks to OKB Grigorov for the opportunity to review this unique subject.