A part-built 2 1/2 inch gauge 4-8-2, based on the Joslin/LBSC design for a three cylinder 4-8-2 "Mountain" locomotive.
James Joslin of Canada and LBSC had a long-running correspondence; prior to "Ursa Maximus" he had commissioned the 4-8-4T design which was to become "Helen Long", published in 1927. LBSC described the new design as "A shock for Swindon"!
Work to date is to a good standard, and comprises:
Still plenty of work to do, but an interesting and, nowadays, very rarely seen model ("Helen Longs" aren't much more common either, we've had one complete engine and two part-builts in the last twenty years).
A large locomotive, it weighs in at just over half a hundredweight in its current state. Copies of the original drawings are still available from the National 2 1/2 inch gauge Association.
| gauge | 2 1/2 inch |
| length/inches | 32 + 21 |
| width/inches | 5 1/2 |
| height/inches | 8 |
| weight/kg | 26 |
| wheel material | cast iron |
| axlebox type | plain bearing |
| cylinder material | 3 x gunmetal |
| valve type | piston |
| valve gear | Walschaerts |
| reverser type | pole |
| CE mark | n/a - non-commercial |
| boiler type | locomotive with combustion chamber |
| boiler material | copper |
| superheater(s) | 2 |
| hand pump | 1 |