GPS speedo's for steam loco's???

Also 8274 has GPS speedo as per WSR engines, I think all steam locomotives should have some form of speed recording even if it is just to help police crews.

 

Yes, this speedo, which has seen several fitments including those quoted by 8 RPH, was an in house design which we came up with for 4965 back in 1997. Genuine BTH speedos and GWR bracketry have been in very short supply for quite a while now as there were only a limited number in Barry on the Castles, Kings and the odd modified Hall. I personally disliked some of the fitments of DMU Smith Stone equipment to GWR loco's at that time, such as Manors as it just did not look right. As we were is possession of the GWR drawings for the bracketry and drive gear it was fairly simple to replicate it all exactly as per original and to the come up with a housing that had the same external dimensions, but which was subtly modified to incorporate a simple shaft with sealed ball bearings and a toothed wheel and proximity sensor as 8RPH describes. So the mechanical bits were easy, what was a little more difficult was the electrics. This was sorted by Dave Smith, one of our volunteers at the time (sadly no longer here) who was a cross between an inventor and an electronics genius. He manufactured a number of bespoke printed circuit boards which were populated with bits from Mr RS, and which drove a proprietary meter enclosed in a cast aluminium housing of the same size and similar configuration as the original BTH housing in the cab. All in all most people do not spot that it is not an original, and we are well satisfied by that, which was the original intent.

We have never had any real trouble from this kit over what is now tens of thousands of miles, it meets all the group standard requirements for accuracy, and more importantly is capable of providing the mandatory feed to the data recorder, which is something that I would suspect would cause not a little headscratching with a GPS version. Personally I would not even consider a GPS fitment for our loco's.

As a matter of interest the TLW system has been fitted to 4965, 4936,4953, 9600, 7760, 7752, and 5553. The fitment on 9466 was based on our pannier bracketry and drive IIRC, but Dennis (I suspect) was blessed with having at some previous time visited the well known purveyor of spare parts in South Wales, so the 94 is fitted with a genuine BTH speedo set up.

With regard to the original BTH fitment, we were fortunate to possess an original generator and bracketry for 5043, but sadly did not have a gauge until not long before it was completed in 2008, when we were immensely fortunate to have a genuine GWR gauge in perfect order donated to us by a long standing personal friend. Considering that this equipment is now probably 80 years old, it is stunningly accurate and absolutely rock steady in its indications. Why have a flash electronic gadget from Halfords or whoever when you are blessed with classic British engineering at its best?

Regards
Bob

 

Great post but would be nice to see some pictures of what you describe as it hard to visualize just from the description.

 

I have one of these just as a reference for when driving. It comes supplied with a suction pad and short flexible arm (for attaching to car windscreen) which I removed and replaced with a very strong magnet like this which allows it to be attached in any loco cab, just to the side of or below the spectacle glass, or on the tender/bunker when travelling in reverse. Simple on/off switch, mph/kph switch and a USB socket for charging - no other features which could constitute a distraction in the cab. I know it isn't absolutely 100% accurate, it updates approx. twice per second, and occasionally flashes up an 'unlikely' reading, but generally it's a pretty good guide, and my logic is that as the driver, why shouldn't I have some kind of indication when I have potentially 300 passengers behind me, any number of whom could have a GPS speedo app running on their phone! LED display, so is perfectly visible night and day. Easily lasts a full day on a charge. I've not had any problems with it in 2 years use on steam locos.

 

A volunteer on the Ffestiniog is developing a GPS speedo that will look like the BR Smiths-stone box with analogue dial. Doesn't work in the tunnel of course but then it's dark anyway.

Tim

 

I suppose that if one were very GPS dependant a GNSS base station could be located at each end of the tunnel - at least a straight tunnel. I'm sure it won't be useful or cost effective for preserved lines yet, but maybe the time will come.

 

I wouldn't rule out a motorsport data logger either. These can absorb and store all sorts of channels of info and data from various sensors (including wireless ones), so as well as measuring location, speed, altitude, inclination, braking force, acceleration etc. they can also record and display a whole bunch of vehicle readings such as temps. pressures and vacuums. Cost isn't as high as what it once was and they are designed to be compact and robust.