Even allowing for those things, the schedules were still not exactly tight once you take into account the more restricted running speeds in those locations.
Quite. FGW's approach to performance issues was not to address the issues but to add more performance "fat" to the schedules. Of course, all that did was embed the sloppy operating as normal.Even allowing for those things, the schedules were still not exactly tight once you take into account the more restricted running speeds in those locations.
The two morning services which did Swindon-Paddington non-stop (re-introduced after a couple of years on FHW where nothing omitted Reading) only averaged about 80mph from memory, hardly taxing. GWR Castles could make that kind of performance back in the 1930s for goodness' sakes!
There are no official stats published to prove this, but many drivers reckon the Valentas had better low-down acceleration than the MTU engined versions.Depends exactly what hp they were putting out, a loadbank test of an ex-EMT VP185 power car had the power car producing, in Notch 5, a continuous output of 1,814hp at the traction motors. The continuous rating is 1,770hp - so in my view it would depend more on how well maintained the engines were rather than simply their age.
Some Deltic Napier engines were found to be inadvertently churning out close to 2,000hp in preservation after overhaul!
Know wildly off topic but unless engine set up on a load bank power can vary considerably. Rumours were some class 50s were producing in excess of 3000hp if set up in a depot with no load bank. This was backed up by some people doing performance tests on the train hauled by said locos. Be interesting to get some preserved locos on load banks to see what they are producing as probably almost all set up by hand but that's for another thread maybe?Depends exactly what hp they were putting out, a loadbank test of an ex-EMT VP185 power car had the power car producing, in Notch 5, a continuous output of 1,814hp at the traction motors. The continuous rating is 1,770hp - so in my view it would depend more on how well maintained the engines were rather than simply their age.
Some Deltic Napier engines were found to be inadvertently churning out close to 2,000hp in preservation after overhaul!
The other factor is that the railway became much busier over time - on the Paddington to Reading route 4 Heathrow Expresses were squeezed onto the fast lines from 1998 using 100mph stock, not to mention the half-hourly Cardiffs and others. More trains on the same infrastructure can lead to longer running times as trains become more prone to meet restrictive signals and therefore run more slowly.Even allowing for those things, the schedules were still not exactly tight once you take into account the more restricted running speeds in those locations.
The two morning services which did Swindon-Paddington non-stop (re-introduced after a couple of years on FHW where nothing omitted Reading) only averaged about 80mph from memory, hardly taxing. GWR Castles could make that kind of performance back in the 1930s for goodness' sakes!
Yeah yesterday I was trainspotting at Cardiff Central and all of the 2 tph Paddington services I saw were operated by 800s or 802s. Some arrived from Paddington on diesel mode, probably didn't bother raising the pantograph after switching to diesel before the Severn Tunnel.
In the perfect world the HeX services should really have been 125mph EMU's - especially as the Class 800's now have equal acceleration to the 387's.
I would have thought the app would be more accurate as it's purely a mathematical calculation and there's nothing mechanical (such as measuring wheel rotations) involved. Especially when travelling in a straight line - on a curve granted the GPS might give a slight under-reading as the straight line distance will be shorter than the distance actually travelled and it might think you haven't travelled as far as you actually have. I suppose it depends on the interval over which the GPS determines the speed (I don't know this but suspect it's only a few seconds therefore fairly accurate).
Accuracy will also depend on how accurately the GPS device can calculate its position, which in turn depends on how many satellites it can 'see' (I think). Even sat here in my house, my phone thinks it's several metres away from where it actually is.
GPS needs a clear sky view. Sat in a tin box it will only see a few satellites. Some buildings are also effective radio black holes. My house has thick stone walls and no radio (Mobile, VHF)radio gets inside.
I've got news for you...
I've got news for you...
...'the sticks' are being rapidly covered with bricks and mortar, steel, concrete and glass. Soon the Borough of Paddington will be seen to be an integral part of the city of Westminster.
To lose that much time it's very probable there was an engine out. Quite possible a second one wasn't 'giving its all' or indeed out as well. When all engines are working they keep to time without much trouble.
A professional GPS speed measuring device such as Racelogic Vbox and its derivatives use Doppler shift within the GPS signal primarily to calculate speed - rather than position. If the antenna is located in the centre of the window with a good view of the sky, the results are surprisingly accurate - possibly more accurate than a train speedo - where the train speedo is reliant on a specific wheel diameter. These devices rely on an external antenna the size of a matchbox and some sort of ground plane. Or a ground plane antenna that is the size of a 10cm plate.
I understood from various GWR drivers on this and other forums that they would drive more cautiously to avoid ATP braking interventions - which could occur at close to 125mph on trains with worn wheelsets.
Does IEP bi-modes have enough installed power for their weight and for hotel power. Does the diesel kit have the correct characteristic to deliver power across the speed range?Just to add my comment on this, I had my first experience longhauling an IET on diesel mode just before New Year heading down from Paddington to St Erth. I find it quite surprising to see the posts above because the difference in acceleration between diesel mode and electric was a lot more substantial than I expected. While I know of a couple of gradients that are steep on that route, there must have been at least a dozen separate occasions where even at full power the unit was decelerating, at relatively low speeds too, probably below 40mph at a few points (identifiable by the controller for the traction motors changing modes and the unit continuing to slow down for considerable time thereafter.) Although the service was delayed anyway due to a change in calling pattern, almost every single stop lost time once on diesel mode. I suppose it's possible there was an engine out somewhere in the formation but as a 9-car unit I wouldn't have expected this to have been as drastic as it would be with a 5. Certainly, the 150 I travelled the route on last time round felt considerably faster. I know you'd get much more of a sense of speed on a rattly old thing like that, but hearing the GU running flat out for about three minutes solid and looking out the window to see the scenery crawling past was eye-opening to say the least. I'm sure HSTs performed way better than this.
This is the service I was on
Realtime Trains | 1C86 1504 London Paddington to Penzance | 30/12/2021
Real-time train running information for 1C86 1504 departure from London Paddington to Penzance on 30/12/2021. From Realtime Trains, an independent source of train running info for Great Britain.www.realtimetrains.co.uk
Oh yes, a 9-car would usually need all 5 engines to accelerate up the Devon Banks. Any less and they do indeed slow down on the way to the top. Not unusual to experience a 9-car on 3 of 5 engines feeling like it's going backwards.Just to add my comment on this, I had my first experience longhauling an IET on diesel mode just before New Year heading down from Paddington to St Erth. I find it quite surprising to see the posts above because the difference in acceleration between diesel mode and electric was a lot more substantial than I expected. While I know of a couple of gradients that are steep on that route, there must have been at least a dozen separate occasions where even at full power the unit was decelerating, at relatively low speeds too, probably below 40mph at a few points (identifiable by the controller for the traction motors changing modes and the unit continuing to slow down for considerable time thereafter.) Although the service was delayed anyway due to a change in calling pattern, almost every single stop lost time once on diesel mode. I suppose it's possible there was an engine out somewhere in the formation but as a 9-car unit I wouldn't have expected this to have been as drastic as it would be with a 5. Certainly, the 150 I travelled the route on last time round felt considerably faster. I know you'd get much more of a sense of speed on a rattly old thing like that, but hearing the GU running flat out for about three minutes solid and looking out the window to see the scenery crawling past was eye-opening to say the least. I'm sure HSTs performed way better than this.
This is the service I was on
Realtime Trains | 1C86 1504 London Paddington to Penzance | 30/12/2021
Real-time train running information for 1C86 1504 departure from London Paddington to Penzance on 30/12/2021. From Realtime Trains, an independent source of train running info for Great Britain.
Thanks Clarence. Your inputs as always appreciated
