This is an outline drawing of my next loco project - I'm still waiting for copies of the original "works" drawings, in order to begin planning my 1/8 scale Live Steam model of it...

I haven't yet decided which type of tender to build - originally, this series of Finnish "Hv" (acronym for "passenger, medium-weight") engines had three versions, the first two almost identical, with 3-axle tenders. The "Hv3" type had a 4-axle, two-truck tender. In the drawing, I have only simulated the longer tender, so it's not a correct drawing!

This photo is from an encyclopedia printed in 1919, and shows Hv1 No. 565, built by Tampella in 1916, one of the first locos of this series. Altogether, 99 locos of the Hv1-3 sereies were made in 1915-1939. A few are preserved, and Hv1 No. 555 is kept in running condition at the Finnish Railway museum in Hyvinge.

Even though I haven't started the planning work in earnest, I have already obtained the boiler tube. It is copper-nickel, cut and formed from a larger diameter tube, and TIG welded to obtain the final diameter of 185 mm (with lagging and wrapper, it will be exactly 200 mm ( 7.9") in diameter.

As you can see, this time I'm going to build a proper firebox boiler. Maybe it will be coal fired, who knows? But I'm certainly going to try building a propane burner to fit and work in the firebox!

One drawing so far... The frame of the HV series locos:

I'll keep you informed of the progress on these pages...