35028 Clan Line returns: 27/04/24

All looks very commendable. Interesting that the return calls at p2, not p1, at Woking - unusual in recent times?

 

I note that, despite the down run being commendably fast, RTT shows it as planned for 60mph max. Now I know all the talk about RTT's timings and max. speeds not being a linear relationship, but this one looks odd - surely it IS planned for 75mph given its timings from Wimbledon to Salisbury?

 

Wimbledon to Salisbury looks flatter than the route yesterday having reviewed my gradient profiles. If it was timed diesel free yesterday then acceleration would be far slower so that may be the reason.

 

I think it means its timed for 60 mph which is not the same as maximum speed 60 but I don't know why they do that. We got up to 75 between Asford and paddock Wood yesterday.

 

I think there's two different things. The first is what number you need to put into a computer model to generate the right passing times to fit the path and the conflicts. 82 mins for 76 miles, the nearest is probably 60 mph.

Then there is the max permitted speed. That will be planned for 75mph. Given the gradients you couldn't do that schedule with a max of 60. Even time from Raynes Park to Tunnel Jct will be a fine run.

 

Not being involved in this, but having seen a similar thing with timing speeds from a similar operation with D1015 recently. The argument for the lower timing speed was a degree of assurance in a loco fresh out the box. Not to say of course that the loco won’t be taken to its registered max, nor that this would reflect any future operation.

 

I understand from the latest Pathfinder tours email that D1015 is now limited to 75mph rather than 90mph (owner's choice) and all her trips will now have a class 50 on the back for insurance - this may dictate the lower pathing speeds.

 

Indeed, my response was a comment on @Will RL post that D1015 had slower timings on a recent trip.
The majority of steam trips are timed at 60mph and 700 tonnes trailing weight to account for the slower acceleration performance compared to more modern traction, despite many being capable of 75mph.
If D1015 has had its maximum speed dropped from 90mph to 75mph and now needs to take a Class 50 with it everywhere too, I wouldn't be suprised if it too was now timed at 60mph also.

 

I’m not sure that’s correct. I understood that the NR computer has no category of steam locomotive so it shows as a diesel and the load is the maximum that can be worked on the particular timings. The norm seems to be 715 tons.

 

Is the class 50 not on the back to primarily provide an ETS (Electrical Train Supply) to the train? As I recall, I don't think "Westerns" had this capability.

Peter

 

I think we are all trying to make the same point but coming from slightly different angles!
-No NR don't have a steam loco category, so use nearest comparable performance characteristic (diesel, trailing load 715t)
-The maximum timing speed isn't necessarily the maximum speed of traction, but again reflects most likely performance to get most efficient path.
-D1015's reduced maximum speed will result in slower timings!

 

From Pathfinder email regards 'English Riviera Air Show', 1st June:

"The train will be timed to run at 75mph with load 12 and a Class 50 on the rear for insurance. We are told that this will be common practice for every railtour with D1015 moving forward."

It ran with a 47 on back for test run, guess this is a dual function for ETS and insurance, but looks like a formal tie up with the Fifty Fund to provide a loco for all Western trips.

 

The timing speed simply shows what's been asked for.

I used D1015 as an example as it’s something I can relate to in 35028 also making its return and could share possible understanding.
Ref the Western, discussions with the loco owning group and TOC were that during the locos first season out, the timing speed would be 75mph. This is just so the loco isn’t required to work to its limits upon its immediate return to the mainline. The loco is passed for 90mph, and can achieve this if line speed permits. The 50’s owning group aren’t keen on ETS supply, Riviera have a generator car that can supply this. I spec’d the cl.50 to be the support loco as both locos could come from the same place of origin, thus reducing resource requirements (i.e. two crews to bring two locos from two different locations).

Some thread drift… but perhaps informative?

 

I understand that, but, for what everyone agrees is a fast run on Saturday, being timed for 60 just seemed odd, even though it will get to 75. There have been plenty of slower steam runs recently with 75 shown on RTT. Only curious - not a big thing.

 

There's a certain maroon class 69 that might be good to use (won't happen, obviously)!

 

It was a test run so things were taken easy at first and gradually the engine was given a bit more, that could be the reason for the easy timings. I don’t think the difficulties in coupling up in Battersea Loop were foreseen but that delay was made up and we arrived back early.

 

I didn't mean the test run, but rather that many steam runs recently have had 75mph timings on RTT but with slacker schedules than Saturday 27th's.

 

I suspected that. Anyway, only curiosity and won't matter on the day.