North Yorkshire Moors Railway General Discussion

Given good rail conditions, Repton will drag 7 up the hill to Goathland in both directions. However, any reduction in adhesive ratio becomes a problem. In theory, you need 13,538 lbf darawbar pull to drag 7 full coaches up the 1 in 49 and 6,648 lbf for the loco, giving a required tractive effort of 20,186 lbf. That compares well with the quoted T.E of 25,130 lbf. The loco only has an adhesive weight of 42 tons, though, and that translates into needing a coefficient of adhesion of 21.4% to avoid slipping. Compare that to a Black 5 which works out at needing 18% to do the same job. On polished rails, whether wet or dry, you are OK but on rails which have not been used for a while, (i.e. since yesterday) you have no chance without sand to artificially improve the adhesion. Schools have the luxury of sands to all four driving wheels in forwards but they do get blocked and it does depend on exactly where on the rail it is deposited as to how effective it is. In reverse there are no steam sands and you are reliant on the tender gravity sands which, in my experience are fairly unreliable, easily getting blocked, even when they were working when you left shed.
Thos figures quoted are for the 1 in 49. However, @Ploughman tells me Greenend is actually 1 in 41 and Darnholme curve is 1 in 42/43, both for long enough to have the whole train on and these are the favourie spots to slip to a stand going southbound, along with Beckhole under the trees.

 

I think this comment really goes to show that there must be something reasonably special about the NYMR for its supporters to spend large amounts to support it. At one time or another it seems to have an unerring ability to upset them, though, and they don't really seem to learn. Nowadays they seem to be focusing their efforts on destroying the support from volunteers and supporters via donations and bequests, and as far as I can tell, they are down to just one "major" supporter, so it has to be hoped that their "professional management" are equally good at being "professional fundraisers". If their timetable planning and marketing efforts are anything to go by, things are desperate!

 

Would they not have used D49s on the line in pre-closure days? They seem not much different from a Schools in driving wheel diameter and adhesive weight, albeit less powerful. Don't know about this running tender-first business - I'd have thought the furthest a Schools ran like that back in the day was light engine from Bricklayers Arms to Charing Cross..

 

D49’s were indeed regular performers. The big difference was that the maximum load without assistance was five coaches and that included B1’s and Black 5’s. Most trains would be less than that.

 

SR V "Schools" Class LNER Class D49 ("Shires" / "Hunts")
Total Built 40 vs 76
Boiler Pressure 220 psi vs 180 psi
Tractive Effort 25,130 lbf vs 21,556 lbf
Loco Weight 67.10 vs 65.11 long tons
Axle Load 21.0 vs 17.8 long tons
BR Power Rating 5P vs 4P

 

Are you sure about those weights? It seems odd that a D49 is only two tons lighter overall, but has more than three tons per axle less axle load. If right, it implies about 15 tons on each bogie axle, which would be a very odd weight distribution.

Tom

 

According to Wiki (and to save me doing better research at this time of night) the D49’s had a total adhesive weight of 42 tons, the same as the Schools.

 

23T 11C for the front bogie, 21T 5C for leading drivers, 20T 15C for rear drivers.

 

Hands up - I lazily Googled it without a thorough fact check, which I should have done as I also raised an eyebrow.

 

It shows Mr Gresley really wasn't trying very hard when I comes to loco design

Tom

 

Although I agree with your broad premise, trying to think what the GCR/Trust owns which might be more appropriate or even suitable. Only 48305 or ex NYMR resident 92214 spring to mind.
Everything else based at the GCR is owned or looked after by groups affiliated to the railway.
SLL and 80104? Still not a great swap for SLL/Swanage.

 

Er..... please get the facts right, Tom. The D49 Shires were on the drawing board by 1926 with the first entering service in 1927. That was about the time that Maunsell was looking for ideas for a powerful 3 cylinder 4-4-0 loco and it is fairly obvious that Gresley's D49 was the sort of thing he was looking for and was the inspiration for the Schools. It was a further three years before they entered service.

 

Maybe the NNR with their WD? For my own part, though, I think that Repton is a perfectly OK engine for the NYMR under most conditions and there's no need to do a swap! Just judge the days when it is used a bit more carefully, or at least don't put it on the first train of the day!

 

In the war my Father travelled over the Wolds to Bridlington behind a D49. He told me the train was 17 vehicles (not all bogie coaches). He told me that at some of the stations he wondered if they would ever get going again.

Sent from my SM-A356B using Tapatalk

 

I think @Steve has scientifically explained that a 4MTT is more or less optimal for NYMR services followed by tender engine equivalent, black 5s if you're trying to standardise a fleet. A long way from what Repton is ....
In a WIBN fantasy world Horwich/Stanier moguls would probably be ideal. I'm guessing Whitby is the reason Black 5s have been more popular than 8fs at the Moors because from Grosmont to Pickering I'd reckon the freight Stanier would be a canny machine for the job.
Think Steve has also said S15 and K1 well liked. Think there was an offer to take the K4 on but the owner was adamant it was getting plinthed, sadly.

 

17 vehicles up Enthorpe Bank must have been a struggle!

 

The reason Black 5's are more popular than 8F's is probably quite simply because the Railway has always had them 'on the books' with 44767, 44806, 45212 & 45428 being long term residents over the years. 8F' have only ever visited for galas or other short term reason.
Putting aside creature comforts, an S15 is an ideal loco for the line; well up to the job and very sure footed. I had a day on 42765 at a gala many years ago and I can well understand why they had the 'crab' nickname. With a full regulator and a long cut-off it really rocked from side to side. It was sure footed, though. With their small wheels, the K1 & K4 were masters of anything the NYMR could hang behind them and firm favourites for obvious reasons.
I've slipped to a stand twice in my time, both on Darnholme curve. The first was with 45428 on my first ever official driving turn with 7 on. It was an autumn gala with the first train and rail conditions weren't good. I took some comfort in the fact that the first train from Pickering also slipped to stand so it was real fun and games sorting things out with a banker being sent from Grosmont to help us and then going into Newtondale to rescue the other train. My second occasion was with 71000, again with 7 on. The loco had been prepped by the support crew and I specifically asked if they had tried the sanders. It was a drizzly day and we started slipping at Beckhole so the sands went on and all was well. At Darnholme it started slipping again, even with the sands on and we came to a stand. The support crew guy said we've probably run out of sand and when I said I thought you'd checked them, he said We checked that they work but we never bother filling the boxes on heritage railways! I tried to restart the train and, after several attempts we slowly but surely got the train off the steep bit and managed to drag it into Goathland. The support crew filled the sandboxes full when we got back to Grosmont! There ought to be film of that somewhere as there were plenty of people watching from the hillside.

 

What I meant really Steve was that the Railway has acquired Black 5s, sometimes through benefaction. Clearly there are more 5s than 8fs and I don't think a complete ex BR 8f has ever actually come on the market.
That said, there has been several imported plus two ex Barry that were later "available".
So expediency has really has favoured Stanier 5s over 8s but in terms of standardisation around one of them the latter might, theoretically, be better suited.
Spent many a happy day on 42765, but only a few times on ELR did we open it up like you needed to and, yes, it did waddle! Like you and the S15, the 'Crab' was entirely masterful of the work it was put too. A real shame that after 10 years faithful service its only seen a couple of years use in the following [almost] quarter century ...

 

42765 may waddle but it couldn't half steam. I had a very memorable day on it on a three tripper firing to John Fletcher when it visited all those years ago. Looking at those big cylinders I thought that I might struggle to keep up with Fletch but not at all - just grabbing hold of the shovel seemed to make it steam. I was favourably impressed with it - as well as Fletch's stories of working Blackpool Illumination specials with them back in the day (those who knew him will remember his endless tales of the rails).

I agree, Danny, its a pity it has been sidelined for so long now.

Peter