That's a very unusual engine Bill but a most interesting one from my point of view…

There was a 5" Sentinel serialised in ME a few years back (Sirena) where the builder used a Stuart-Turner Twin for the motive power, mounted up front as in the original Sentinel 100HP prototype. I looked closely at this design several years ago when myself and some colleagues (from the Gauge 3 Society) were looking at developing a Sentinel 'starter' loco for G3. On closer inspection the Sirena wasn't quite near 'scale' enough for our highly refined sensitivities though…

So we started over again (twice!). Fortunately (via this website) eventually we manged to contact someone within the Sentinel Drivers Club (the Road going types) who very kindly found some original GAs for the bunkered version of the loco. These were photographed and emailed to us. I then redrew these full-sized in CAD before scaling them by 1:22.6 (exact scale for 2.5" track!). We then built two prototype engines for test purposes – I built two simple motor/frame sets and John made some excellent moulds from which resin body parts were cast. Then (as seems to happen sometimes) the project kind of went to sleep for quite a while – a bit like Sleeping Beauty really.

Anyway, last year the G3S decided to have a small batch of these engines made as RTR Battery Electric locos (with R/C controls) and these were on display at our Flitwick AGM this past weekend. Our original intent was really to provide a very low-cost 'kit' of parts but unfortunately it seems many folk just want RTR to run these days – hence the decision to offer only RTR locos. However, they are very nice little locos, ideal for a small shunting layout indoors or out in the Garden. We think they are still pretty good value (£660 plus shipping – less to G3S members) but as I mostly scratch build I don't really have a good feel for such things. Anyway – for details see the Gauge 3 Society website here – G3 Society

I'd still like to build a G3 live steam version of the Sentinel, although I don't think I'd get a ST engine in it (or a Uniflow one) but I do have a Bowman-Bryant (valve-less) twin cylinder engine that might fit – although it seems a pity to hide it away under the hood of a Sentinel somehow (memories Bowman steam launches on the boating pond at Guildford's Stoke Park still linger from my 'Youff' )

BTW – as may be gathered, we had real problems getting good drawings of the Sentinel 100HP – and I have some quite good scaled drawings (PDFs) that were distributed to the others during the project that someone who wants to build a Sentinel (in any scale) might find very useful. If so, please PM me – and I'll dig them out.

Regards,

IanT

Edited By IanT on 05/03/2020 14:08:07

Fantastic, someone buy it and do us a write up in ME!