56xx released.

[dorlan]

0-6-2 were first introduced into the Valleys by the TVR in 1885, primarily for coal traffic.
They were engines that had the majority of their weight available for adhesion. The trailing axle enabled them to have a larger bunker, which gave them sufficient range, due to the extra coal, and also the extra water they could carry, to travel to the docks from the furthest pits at the tops of the valleys.
High speed was not necessary, even on passenger duties, so a leading pony truck wasn't needed.
The shorter wheelbases involved were also advantageous.
In 1922, the pre-grouping companies owned 400 0-6-2s, 50% of their entire stock of locomotives. The GWR added a further 186 0-6-2s, the 56xx class, between 1924 - 1928.
The 56XXs were based on a blend of the Swindon No.2 boiler and a modernised underframe with an identical wheelbase to the Rhymney Railway R class, which at the time, were the most powerful valley 0-6-2s.
The 56XXs were regularly seen on loaded coal trains of 900+ tons heading down the valleys, hauling 60 empty wagons back uphill, on normal passenger workings and on heavily laden excursion trains.

[black8]

.... The other one is the reverser, as times when regulator is open and attempt to change reverser setting it does leap as in the manual, but I am not sure if this would happen on a flat, as this never happened when driving 3850 in 2nd valve.

Just a little hint for changing the cut off setting on the 56XX. The reverser handle will not 'jump/leap' at regulator settings of 35% and below (F4 reading). Not sure if this is in the manual, or mentioned in this thread already, but thought to let you all know. Makes it a bit easier to change cutoff without losing too much speed; so reduce regulator to 35%, change cut off and increase regulator again. With a bit of practice this goes very well.
Jos

[stuart666]

.... The other one is the reverser, as times when regulator is open and attempt to change reverser setting it does leap as in the manual, but I am not sure if this would happen on a flat, as this never happened when driving 3850 in 2nd valve.

Just a little hint for changing the cut off setting on the 56XX. The reverser handle will not 'jump/leap' at regulator settings of 35% and below (F4 reading). Not sure if this is in the manual, or mentioned in this thread already, but thought to let you all know. Makes it a bit easier to change cutoff without losing too much speed; so reduce regulator to 35%, change cut off and increase regulator again. With a bit of practice this goes very well.
Jos

I think it mentions it at some point in the manual, but I cant remember if it specifically says 35 percent or not. You are of course quite right, it is one option to not loose power on the slope.

Incidentally, there have been a lot of very interesting points brought up in this thread. Been very interesting reading it.

[Mazza35]

By changing the cut off, do you mean the reverser?
Because if you do, I'm fairly sure you can change the reverser while under power...

[Kromaatikse]

Most locos have a screw reverser, which can be changed under full power but takes a long time to wind from full-forward to full-reverse (as is common during shunting). The 56xx (in common with most GWR tanks) has a lever reverser which gets pushed around by the cylinders if under power (hence the catch), but with power off can be adjusted to any setting very quickly.

It is no doubt *possible* to change cutoff while under full power, but it would probably require the combined strength of both footplate crew - and would thus be reserved for emergencies such as a stuck regulator, which is not modelled in Railworks.

[Mazza35]

Ah, righto. I just thought because on our loco (PBR, 2 foot 6 2-6-2T) we can adjust our reverser with a little bit of difficulty, now that i think about the size of the locos, yeah. Where they made when Stephersons gear was the norm or did GWR not like Walschaerts gear?

[Kariban]

I think stephenson was more suited for the job, really, slow speed and large cutoffs. Screw reversers aren't totally safe from running away under power either.

[Kromaatikse]

GWR tended to prefer Stephenson gear (or the close variants) in general - it was even used on the big Castle and King locos, as well as the smaller mainline types such as Hall. Nearly every other railway used Stephenson gear on small locos (up to typical 0-6-0 sizes) and Walschearts on large locos. The BR Standards all used Walschearts, even the relatively small Class 2s, except of course for the Duke.

Quite a few large mainline locos went to the trouble of providing power-assisted reversers. These however often went wrong, and so I believe Riddles simplified the mechanism substantially for the Standards as well as the rebuild of the Bulleid Pacifics (whose steam reverser was particularly notorious for leaping into full gear without warning). I'm not certain of how simple it was made on the large designs, but a simple screw with a locking catch seems plausible for at least the smaller types. The screw would enable the handle to be controlled by the driver even under full power, and the catch would prevent it from drifting when not being adjusted.

I don't think I've ever heard of simple screw reversers leaping around of their own accord - although they could be very tiring to operate for shunting. The tales I've heard have all involved some kind of power reverser, which suggests to me that some pretty poor designs were made and put into service.

[metrobus]

As Far as I am aware all screw reverser locos have some form of locking mechanism, to stop the reverser drifting a bit while the regulator is open, although it is worth noting with the regulator fully open, it may be difficult or maybe impossible on larger engines to link up the reverser, meaning the regulator would have to be closed a bit.

Also of interest some locomotives had better screw reverser than others, take for example the LNWR Cauliflower which took 26 turns of the reverser to go from full forward to full reverse , meanwhile the Lancashire and Yorkshire Saddle tank ( class 23 ) of similar vintage took merely 4 turns to go from full forward to full reverser.
Regards
Edward

[stuart666]

I certainly read of one incident using a Saint class locomotive that was being run on a high speed light engine test, and the regulator and the reverser locked under full power. It reportedly took the 2 crewmen and a couple of other people on a jolly on the footplace to pull the regulator back.

Reportedly it touched 125mph going downhill from Badminton. Believe it or not.

[metrobus]

Must have been Pretty lively on the footplate at that speed especially light engine surprised they weren't bounced clean off
Regards Edward

[alexnick]

I certainly read of one incident using a Saint class locomotive that was being run on a high speed light engine test, and the regulator and the reverser locked under full power. It reportedly took the 2 crewmen and a couple of other people on a jolly on the footplace to pull the regulator back.

Reportedly it touched 125mph going downhill from Badminton. Believe it or not.

Any good sources for this story? It sounds interesting

AN

[metrobus]

Well since it was light engine, there wouldn't be a dynamometer car, and even if the loco did have a Speedo, it's unlikely to be accurate. So It's very hard if not impossible to validate the story, could have been going 70mph for all we know and the driver may have been exaggerating a bit
regards
Edward

[stuart666]

It was refered to in 2 books, both I think by WA Tuplin (who spent a lot of time on the Swindon static test rig I gather) but I would have to check on that. Its hard to know how true it is. Supposedly GWR hushed it up because it was a rather informal trial (little more than a bet I gather) and one of the men on the footplate that day was supposed to have been Charles Collett, which would have been something like 15 years before he became CME, so it was not something he was likely to brag about. Indeed when he was questioned about it in the 1930s he allegedly confirmed it, but was rather embarressed about the whole thing. They were lucky to get away with it.

I gather the timing was based upon books kept by the signal boxes along the route. How accurate that is depends on how accurate the timekeeping actually was in those boxes. Though I suspect that having a machine crash through at 120mph was probably enough to ensure accurate timekeeping!

I doubt it was as low as 70 mph, because saints often exceeded that in service hauling expresses. Just running light engine it seems possible it topped 100mph, although as it wasnt hauling anything it would hardly qualify as a speed record. Bear in mind, this was one straight out of A shop, which was only just being run in, so the tolerences on it would have been quite tight. Perhaps enough to explain why it was so hard to get the thing back under control.

As I say, im uncertain of the provenance of the story. I only give it credence due to the apparent veracity of the person relating it, and knowing what an exceptionally good locomotive the Saint was. It also illustrates what the forces must have been like in these machines when running at full tilt.

Wonder if we can talk Network Rail into giving it a try?
http://www.didcotrailwaycentre.org.uk/g ... oject.html

[stuart666]

There is a bit more about it here.
http://www.heritagerailway.co.uk/news/d ... at-mallard

One of the reasons why im really very keen for there to be a Saint in Railworks one day. People forget what exceptionally good machines they were. Even if this isnt true, it appears one does hold the informal record for the Cheltenham flyer. Supposedly one managed to make it at least a minute inside the official time. Takes a bit to outrun a Castle on the flat.