Atomic Systems

I think it depends on what era that you use this is mainly a steam era route, as I think it closed in the early 1960s,it just might have seen BR class 20,24,25, and just probably class 37
But of course, as it is a simulation you can run virtually anything you like on it
Mike

rkk01 wrote:Does anyone know what the axle loading limit was for the line / Belah viaduct?

It was pretty low. As far as I can trace, the only locomotves used over the various viaducts were:

• Worsdell J21 0-6-0
• Worsdell J25 0-6-0
• Ivatt 2MT 2-6-0
• Ivatt 4MT 2-6-0
• BR 3MT 2-6-0

They ran in pairs if need be.

John

I know they are including an Ex GER 2-4-0 that was used for a while over the Stainmore route.
Just looked up West Aukland shed

listed loco for the steam era 2MT, 3MT, 4 MT, J26, J39, J71, J72

Up to 1956, there was an allocation of A8 4-6-2T (NER)

Mike

So, if the 4MT has an axle load of 17t...

Then the WD 2-8-0, 2-10-0 or S160 would be fine (by axle load, rather than all up weight)

The axle weight of a standard 4 was 17.25 long tons

Mike

Going by that, even the mighty 9F would be suited for the route, considering she has a axle load of only 15.7t...

The Ivatt Class 4 had a RA 4 and the BR Version as well

Mike

locomotiveman1994 wrote:Going by that, even the mighty 9F would be suited for the route, considering she has a axle load of only 15.7t...

As fas as I know the route availability (RA) of the Stainmore line was raised from RA2 (with some RA3 allowed) to RA4 in 1954, with some engines of RA5 and RA6 allowed (although rarely seen). The 9F's had a route availability of 9...

Marcus

The RA system seems to be somewhat confusing. According to Wikipedia, the 9F has an axle load of 15,7 tonne, with a RA of 9. According to Wikipeda's site on Route Availability, an RA of 9 restricts engines with an axle load of ≤25.4 tonne.
You say the route has a RA of 2, respectively 4 from '54 onwards. With RA 3 limiting to ≤16.5 tonne per axle, the 9F would still be suited for the line, going ONLY by it's axle load.
Could someone enlighten me, please, as I do not understand the logic behind it...

Whilst axle load is the major factor, there are other considerations. Many steam locomotives had minimum curvature limits - ie they couldn't safely negotiate curves with a smaller radius than one specified. This was particularly true of the 9F, which had flangeless wheels on its central axis - otherwise it would have been very strictly limited to where it could safely run. The flanges on the second and fourth coupled wheels were reduced in depth. This enabled the locomotive to round curves of only 400 feet (120 m) radius. I am not sure what the minimum curve radius is on the Stainmore line.
For early diesel locos, many had leading pony bogies on the axles (eg the 1Co-Co1 set for Cl40s) for similar reasons. In game, the AP/RR Cl40 has such a bogie, so can tackle much tighter curves than the DT Cl40, which has the pony fixed to the bogie.

Just a thought could it be the overall weight of the locomotive and tender makes it to heavy for the route
Mike

Surely axle loading has to take into account distance between axles to give an idea of how heavy a load is being put say on a bridge span. Lots of small wheels versus one with few and the same axle load will be completely different weight locos.

I think an engine's RA is also influenced by hammerblow (especially with 2-cylinder engines), as its effect on underline bridges can be more important than dead weight.

Marcus

locomotiveman1994 wrote:The RA system seems to be somewhat confusing. According to Wikipedia, the 9F has an axle load of 15,7 tonne, with a RA of 9. According to Wikipeda's site on Route Availability, an RA of 9 restricts engines with an axle load of ≤25.4 tonne.
You say the route has a RA of 2, respectively 4 from '54 onwards. With RA 3 limiting to ≤16.5 tonne per axle, the 9F would still be suited for the line, going ONLY by it's axle load.
Could someone enlighten me, please, as I do not understand the logic behind it...

I'm unsure how the BR 9F got a RA of 9 as they system was, I think, only introduced with Diesel Locos?

Is the Wikipedia entry confusing the Power rating of 9 Freight with an axel loading?

Peter

My ‘Observer’s Book of Railway Locomotives of Britain’ (1958) gives the RA of most ex-LNER and BR standard engines. The GWR had her own system using coloured dots. Accoring to Wikipedia the system originated with the LNER and was later adopted by BR.

Marcus