dk1
Veteran Member
Drives me bonkers. They are being changed on 13/14 to allow more trains to draw up behind.Agree with that, and some platforms (Man Picc 13&14 for 2) there's that many stop boards it confuses the issue.
Drives me bonkers. They are being changed on 13/14 to allow more trains to draw up behind.Agree with that, and some platforms (Man Picc 13&14 for 2) there's that many stop boards it confuses the issue.
Yeah my point... In the end it ends up making a right mess and it complicates everything.It's all there still. These idiot boards are enforced upon us. They just help to make stations look a mess.
Drives me bonkers. They are being changed on 13/14 to allow more trains to draw up behind.
I'm confused by the difference between the plated unit and individual vehicle weights!
The plate on a 755/4 says the complete unit weighs 163.4t.
But the individual weights of each vehicle add up to no more than 112.2 tons? Either somebody cannot add up or there is an explanation as to why they figures don't reconcile. The vehicle weights as plated are: DMS127.3t, PTS 13.8t, PP 27.9t, PTSW 16t, DMS2 27.2t.
Can anyone work that out? With 3,500 electric horsepower on tap - and 163 tons, that's a phenomenal 22hp/ton. But if the unit weight is only 112 tons, then that's closer to 30hp/ton - TGV levels of power on a low geared 100mph unit - Absolutely bonkers!!!
It had crossed my mind. I just wanted to see if anyone knew definitively. It certainly makes sense!Could those individual vehicle weights be excluding the (shared) bogie weights i.e. total set weight = vehicle weights plus bogie weights?
Stadler quote the installed diesel power as 1920kW which equals 2574hp and 15.8hp/ton.How does a 755/4 compare with other UK dmu's in it's power to weight ratio/(1920 kW & ??? tonnes.)?
I ask 'cos most of their in service mileage won't be under the wires.
Stadler quote the installed diesel power as 1920kW which equals 2574hp and 15.8hp/ton.
The most powerful older DMU's seems be Class 222's. A 5-car unit has 3,750hp and weighs 249t, so power to weight ration of 15hp/t.
But the 222 is geared for 125mph, while the 755 is probably only geared for 100mph.
If you are looking at what the 755;s are replacing - A 2-car Class 170 has 844hp for a weight of 88.4 tons - so 9.54hp/ton.
And a 2-car Class 156 unit has only 570hp for 74.7 t - so 7.63hp/t.
So a 755 has double the power of a 156, and a third more power than a 170!
If we base the Class 755 power at rail figure to be 80% of the installed 2,574 diesel hp, we get 2059hp which is around 12.6hp/t.
Comparing to electric units - the Greater Anglia Class 360s are around 15.8hp/ton, while a Class 321 has only around 10.3hp/ton.
No surprise then that a 755 out accelerates the 321 but is slightly behind a 360 from 0 to 90mph based on real life recordings.
By my reckoning the 755/3 will be 9.4hp/ton installed power - so on a par with a 170 and a bit more power than a 156.Thanks for all of the above info, 'tis appreciated. I'm guessing that the 755/3's with 960 kW / 1287hp, but with 1 car less could at least keep to the existing timings on the branches. They might be ideal (as a pair of 3-car sets)for the through London - Lowestoft workings as (AFAIK) the East Suffolk route has some severe speed restrictions, + when under the wires they would have the same power at the rail as a 12-car 745.........
i dont understand why all the failures and breakdowns only started to occur once they were in service, during testing they seemed to work flawlessly
Yes i cannot imagine the driving vehicles being twice as heavy as the intermediate vehicles. So the vehicle weight for the driving vehicles clearly includes the weight of the end powered bogie.Could those individual vehicle weights be excluding the (shared) bogie weights i.e. total set weight = vehicle weights plus bogie weights?
I've just passed Cambridge station and seen 755 410 in platform 5, presumably waiting to form the 1009 to Norwich. This service hasn't previously been a 755 (normally it's the 1109 that is) - so there's either something unusual today or the diagrams have been changed.
Talk of another two DMU diagrams converting to 755s next week.
I think it would have to be.Or is the weight supported in such a way that the weight is evenly distributed across the bogie?
I think it would have to be.
If the points where the two bodies transfer their weight to the bogie are close together (or even better, concentric), there will be natural distribution of the weight anyway between the axles. Simplistically, a normal 2-axle bogie is a bit like an upside-down see-saw - the vehicle weight pushes down on the centre and the bogie frame will distribute that weight equally to both axles via the primary suspension.
of course. We are not expecting anything tomorrow.You will have to be patient before seeing any reduction of journey times. The lead times for timetable planning are considerable, and neither NR or GA are going to commit to anything without sufficient proven data. Far better to start with to bag the performance improvements first and then look at journey opportunities later when all staff are used to the fleet and they are fully bedded in.
That is ridiculous!! So much for spending millions on new trains and then not dealing with these minor operational issues. I cannot believe it. Which location is that? Am I right in thinking just North of Wymondham - where there is a very slow start and crawl before powering up to Norwich?there are even follies such as reductions of 10mph briefly for signal sightings issues on signals that are no longer there. Drivers have this monitored when downloaded reguardless that it no longer serves a purpose.
No chance of any upgrades on the Wherry lines. Lowestofts turnouts will be 40 instead of 10, Brundall to the Acle branch is 25 rather than 15 & it's now 40up/60dn through Reedham rather than 20/15 but that's your lot.That is ridiculous!! So much for spending millions on new trains and then not dealing with these minor operational issues. I cannot believe it. Which location is that? Am I right in thinking just North of Wymondham - where there is a very slow start and crawl before powering up to Norwich?
Operationally, Trwose junction is a pinch point as is the swing bridge. Also the fact that Platforms 4,5 and 6 all seem to be on the same lead in- which means there is no chance for parallel moves.
I was stuck on a 755 sitting by Crown Point having arrived very early but couldn't get into a Vacant platform - probably because the route was set out of 4 or 6.
Again, the Yarmouth route is crying out for some improvements. The turnout speeds at Acle and at Yarmouth itself should be at least 40mph - rather than 20 and 15mph. The line is so straight it surely is suitable for at least 75mph and even 90mph. No wonder passengers would rather use the car.
where are you sitting in the train?I’m on the 1209 Cambridge-Norwich and it’s a 755. Very impressed, it’s very quiet despite being on diesel.
I was in the second coach, but at the end furthest from the engines. You can hear them a little bit but it’s hugely better than a Turbostar, with no vibration. Reminds me of the 800s in diesel mode.where are you sitting in the train?