Steam Dreams to Bath - 12/03/20

It was very possible and done without exceeding 60mph. Very good climb, it seemed like a TPWS stop before Betchworth as all was good then a sudden brake application.

Andrew

 

In fact, according to RTT, it was actually a full nine minutes gained from Chilworth to Dorking West on a schedule of only 20 minutes that was set for a 75mph loco (limited to 70 on the route). My point is that there must be something wrong with the RTT data.
Interesting if it was a TPWS stop - over-speeding surely not likely here (uphill at 1 in 144 in a 70mph zone)? It certainly made a change to listen to from my garden compared with the usual purr of 'Clan Line' on the Pullmans here!

 

Getting away from Bath this evening towards Box tunnel.

 

Passing Crofton with the outward run:


The ECS for the return passes Newton St. Loe:

 

Smashing performance from 45212 tonight, volume on!

 

It seems to have been timed longer than necessary between Chilworth and Gomshall for some reason, a full 12 minutes when in reality it took a little over 6 hence the apparent time made up.

45212 in fine form tonight over the Surrey Hills, sound from the front coach out of Shalford going some way to make up for work getting in the way of photting it today!

 

I’m confused as to where the 75mph timings have come from? The path uploaded to system was only ever timed for 60mph max. Black 5’s are also now permitted at 65mph on the mainline. At no point did there appear to be any significant delay owing to the locos inability to keep to the schedule?

 

Interesting to hear of the 65mph allowance for 'Fives' - when did that happen? My reference to 75mph was for the original 61306 rostering for the train. It's worth noting that the NDL has a long-standing issue with time reporting - most of the stations en route display erroneous expected/actual departure times for service trains, owing to signal spacing issues, so I suspect RTT reporting is also consequently erroneous - I have noticed this before. Does anyone know more about the alleged TPWS issue near Betchworth last night which provided me with personal aural entertainment from the re-start!?

No - no confusion from me. The RTT output was attached and showed the data. My contention was that the data was wrong, with which people appear to agree. RTT in general does "do steam" - steam triggers passing data points just like any other train. The platform DMIs at Betchworth always show WB trains as being a minimum of three minutes late, no matter what the reality, and the Dorking Deepdene one frequently shows trains as already having left, i.e. displaying the next train even while the previous train is still at the platform and loading passengers! RTT takes its data on the route from a system that is fragile at best.

 

I’m quoting the Rail Industry Standards that is quoted to be updated in December 2017 but seemed to be brought into practise last Spring sometime.
Black 5’s new limit is 65mph with B1’s being limited to 70mph. However I’m given to understand Buck appealed and the 75mph for his B1 was reinstated.
Timing mainline steam again depends on the loco used. When submitting a request to run a tour, while often advertised to run by a certain loco, up to five locos can be submitted for pathing requirements and other operational requirements etc. Therefore in the event of failure or other operational hiccups, another loco can be cleared for running the tour. Within this, AFAIK, a class 5 loco is pathed for 60mph, despite any ability to run faster. This wouldn’t stop the loco running up to its maximum permitted though.
On a side note it’s also why despite a class 8 (passed at 75mph and able to be pathed as such) being advertised for a tour can be seen on a “timed for 60mph max” path as one of the submitted locos that could potentially run the tour, are slotted in the 60mph ability.

 

Bowling along up the climb to Savernake. Enjoy!

 

The NR train planning system doesn't have specific traction type timing loads for steam traction. This is the train header for the Clapham Jn - Bath Spa yesterday -


Timing load 60-TR715

As far as I remember, TPWS does have an overspeed detection function and will apply the brakes if a train passes a speed restriction balaise too fast.

Cheers, Neil

 

RTT use a data feed from NR. Yes there isn’t a designated traction input for steam. It’s often labelled at timed for whatever speed it’s timed for, and always labelled as a diesel hauling an insane load to signify the slow acceleration rates of steam - it has nothing to do with the actual loadings. As has been said upthread, take RTT with a pinch of salt.

 

Departing Bath spa

 

Didnt stop a Virgin Pendalino overspeeding (by an enormous amount) a TSR guarded by a TPWS Beacon. The crew know the route, they know the speed limits, and would be ready to cancel the warning, on the"the hills" there are not that many unexpected ones, so IF it was a TPWS stop it may have been a TSR placement that they failed to acknowledge in time. Who knows, only the crew can tell you what happened.

 

TPWS does have overspeed detection and many a train was 'checked' to a stand in the early days of its use - I remember Clapham Junction platform 10 had several such incidents where 455s were approaching too fast and were stopped halfway into the platform. However, this won't have been the case at Betchworth (unless there's a loco-only TSR there now, as DMUs are certainly passing at normal speed), so I still wonder what did happen (it would be great if it happens again there as the re-start sounded excellent from my house!). Despite it being dark, I very nearly nipped across the road that night to see it pass - I really wish I had!

 

The "insane" load is usually either 455 or 715 tons. In the case of the 'Belmond Pullman' through Surrey 455 is the usual figure and is often an under-estimate - a full 13 coach rake and a dead/idling 67 gives around 600 tons. The limitations of RTT regarding loadings and speeds assumed for timings have been well-rehearsed, but its accuracy for actual passing times is less often an issue and probably reflects the more general timing discrepancies on the NDL.