3.5” NG Conway or Lilla

For my next build I’m erring towards a 3.5” Hunslet style loco. There appear to be two choices, the Martin Evans Conway or the Ross Harrison Lilla. I can find lots of examples of Conway but few of Lilla, similarly there are a fair few published errors in the Conway design but few for Lilla. Fortunately I have magazine build series for both, heart says Lilla, brain says Conway. Help, which one should I go for?

Are you planning to make the boiler or to buy in ready made?

Could be important if buying, check commercial boiler makers to ascertain who can do it as I think Lilla is a little rare and they may not have the plate formers. Be aware that the waiting time for a new boiler could stretch to at least a year and possibly a lot longer, so ask about that as well.

Good luck

There are many big errors in the Conway plans by M.Evans. A guy called Rich, posting under codename "Firebird" is building one over on the HMEM forum. Has had lots of very challenging things in the design to fix, but has coped with it well. Latest trouble was zero room in the design for fitting the regulator disk spring. Major interferences and mismatched linkages in the valve system too.

If you want a trouble free design to work to, Conway is not it.

Can i add a 3rd choice ?

Hunslette by Don Young. 3.5" Hunslet available from Reeves

Lilla comes up quite big in 3.5" because it's a port class Hunslet (i think). Lilla was printed in Engineering in Miniature Vol 1 & 2. and is available from Blackgates. The articles are good as they offer both castings and fabricated versions.

I started to buy the parts for Hunslette but who knows when i will start it.

Good Luck with your choice

regards

Steve

One thing to consider might be weight. Lilla (a one-off loco built for the Cilgwyn quarry) weighed 10 tons 15 cwt in working order, roughly 25% more than the quarry or port class locos which were slightly over 7 tons, and nearly as much as the Dinorwic "Mills" class. I don't know the model weights, but would expect a similar difference.

Brian

cheers guys, some useful information. I must admit I had not seen the DY Hunslette before but I think it’s a little too small for me. I’ll be doing my own boiler, Reeves have a set of flanging plates for Lilla amongst their few remaining formers being sold off which would help. Looking at Station Road Steam the Lilla they sold looks less toy like than the Conways, possibly just down to the individual builder but nevertheless I think Lilla may be the one.

I would second the Don Young 'Hunslette' design, and I don't know why 'Durhambuilder' dismisses it.

It is a huge lump in 5"g, and still quite a huge lump in 3.5", and I speak as someone who did 'Linda' FR 2-4-0TT in 3.5"g.

Another possibility is 'Charles' brother of 'Linda' and 'Blanche' which is I think marketed by Blackgates.

Martin Evans' 'Conway' is a freelance design with lots of errors, and the valve gear is deficient, and it neither something or nothing.

Don Young's 'Hunslette' is a prototypical example of the Quarry Hunslets.

Cheers,

Julian

Boiler bits all ready to solder up, just need to bite the bullet and buy 1/2 kg of CUP alloys finest!

The wheels are simple discs 4” dia, castings work out at £30 ea whereas slices of 110mm bar in either cast iron or steel are £9.00 each. Should I go for cast iron or steel?

Steel will give you better adhesion and be less messy to machine.

John