3 1/2" Gauge Discussion Group

Thanks Neil, very impressed, not having any luck finding anyone who has or is building an A4 Pacific, does anyone know of that person ?

Cheers Rich

I have just joined this forum as very keen on 3 1/2 inch steam locos, I inherited my Dads Henley 0-4-0 which I’ve had running a couple of times but having problems with the cylinders hydraulic locking with water & shearing the 1/16 inch steel taper pins that connect the piston rods to the motion link rod. I wonder if 1/16 inch is a bit small? I can’t see any details for these on the original Reeves drawings? Has anyone else encountered these issues with a Henley?

I’m going to fit cylinder drain cocks to alleviate the hydraulic locking

Dave,

As designed Henley is a slide-valve design so the valves should lift off the sliding faces to allow any trapped water to escape and so prevent hydraulic locking. Have you got enough clearance (approx 1/16" as drawn) between the top of the valves and the valve covers allowing them to lift? Is there enough vertical clearance between the bottom of the valve rod slot and the valve rod itself or is that lack of clearance preventing lifting?

Of course if your father converted to piston valves then that facility is lost & you will have to go for drain or cylinder relief valves.

1/16" pin should be fine - you want that pin to shear to prevent any more serious issues. Supposing that you do indeed have slide valves fitted I suggest that you find out why water condensate cannot escape by lifting the valves off the face first.

Regards,

Phil

Many thanks Phil for your reply,

i’ll check the valve clearances first before I do anything else & that’s a very good point about keeping the taper pins at 1/16 inch so they continue to act as shear pins in case of any further lock ups.

I’ll see if I can post some photos on here of the loco.

cheers, Dae