tgk300

That would give far more weight on driven axles, something which I think the 755/4's will struggle with if ordered for steeper routes.

That is a good point, two single ended half sets would allow more powerbogies as have just two on an 8 car train is not good. I am confused as to what this means, are they suggesting that vehicles used for rail replacement bus services will need to be "accessible", if so, are there actually "accessible" buses around? I cannot see how a double decker can be made accessible, nor a traditional coach. So does that mean that only certain single deckers can be used? So an 8 car Bi-Mode FLIRT would essentially be two 755/4's coupled togther with the cabs on the inner ends removed all the while leaving the powerbogies in place?

Everyone could see this was going to happen, It's no suprise to anyone that they have been given an extension beyond the initial date.

If these units were ordered for another operator that required an increase in length, do we reckon it would be possible to have a 13m powercar with 8 engines and then 8 passenger coaches giving a 160m length? Would this be pheasible or would a TOC be better of ordering a more "conventional" train.

Of course, its just not as big of an increase as some were expecting.

So It seems as though my theory of 36 tonne on all four driven axles is incorrect seeing as that excludes bogies weight on the driving wheels. Still 27 tonnes of DMS coach on three axles, but without knowing the weight of the powerbogies exactly as well as the weight of the jacobs, it's impossible to estimate with any level or accuracy. Is a jacob bogie heavier than the powerbogies, or about the same. Either way, that means that on average each bogie weighs 8.5 tonnes, a fair weight I will say. If you said that tehy powerbogies do weigh 8.5 tonne then you 18 tonnes of car weight on the two axles plus 8.5 tonnes of bogies weight giving 26.5 tonnes, Multiplied by two gives 53 tonne out of 163.4 on powered axles, or 32.5%.

So according to a Railway Magazine article, the 755/4 has 202 standard class seats as stated on the vehicle plate, and then an additional 27 tip up seats. The standing capacity is not stated. Don't forget that this unit is only 80m, and 7 of that is taken up by the powercar. It does seem quite low though.

16 tonne is light, that cannot include the bogies at that weight. The numbers on this unit just don't add up, and again, thank you for taking the time to help.

With on 36 tonne on the four driving axles, and a total weight of 163.4 I would imagine that with all that power it would have some serious wheelslip on other routes such as my local one in poor weather. Tonne (whcih is what I assume to be on the driving axles) out of 163.4 is only 22%, not great for a modern high performanmce unit. It also decreses their power to weight from 22.9hp tonne (2575hp / 112.2), down to a still very impressive 15.8 (2575 hp / 163.4).

Thank you very much, I appreciate you taking the time to take this photograph. So the total unit weight is 163.4 tonne and not 112.2. Confusing.

So are the Class 755/3 and 755/4 units allowed to run to these “sprinter differentials”?

I thought that 163.4 tonne was a slight bit on the heavy side, but apparently that’s what’s on the weight plate. I could see 6 bogies weighing 50 tonne as don’t forget that four are Jacob bogies and the other two have traction equipment in. 112.2 does seem a little light though so I don’t really know what it believe. I would be very great full of anyone local could snap a photo of the weight plates on all 5 cars on a 4 car unit and see what the total weight as one of them will have it listed.

Do you know what the tank capacity of a 4 car unit is? I would imagine that GA were aware of the fuelling issue during the design process but chose to live with it as the increased hassle may of been offset by other benefits.

I can't imagine that GA or Stadler would of designed a unit in such away as to make it's basic day to day operation difficult. Obviously the tanks are small, the powerpack is only 6.69m long so there was never going to be a huge amount of space, especially seeing as the bogies take up a significant amount of that underfloor length. I assume that the fuel tanks are under the floor as there is know where else for them, but what is their capacity? The issue is that all four engines, electrics, cooling systems and fuel tanks are in a 6.69m unit. The issue with the fuel tanks should of been realised from day one.

I have found the page in which I got the idea of the total 4 car unit weight being 163.4 tonnes. This page states it on post no. 3723 https://www.railforums.co.uk/threads/abellio-greater-anglia-class-755s-regional-trains.148431/page-125 They state that the total unit weight is 163.4 according to the plate, but adding up all the vehicle weight plates, 112.2 tonnes is stated. Someone else has suggested that the 112.2 does not include the weight of the four Jacob bogies. 163.4 - 112.2 is 51.2. That would mean that each Jacob bogie weighs 12.8 tonne when connected to the unit. It amazes me that Stadler can make a unit like this only weigh 112.2 tonnes, to me it seems impossible.

Once again, forgive my ignorance as I am not familiar with either the diagramming or the operational procedures at GA, but how much of an issue is the fact that they need daily refuelling? How much of an affect does this have on where the units can be stabled, when/where they will be ready for service and of course their availability?. Does anyone know the capacity of the tanks in litres?

I have read on other forums that apparently these units, especially the four car ones, have rather small fuel tanks when their installed power and expected fuel consumption. Can any one tell the capacity of the tank and how often they need to be filled?

I know they're from the vehicle plates, but they have not photographed two of them and I was wondering if the total weight is stated on one of the two unphotographed plates. Stadler have done an excellent job if a 4 car unit weighs just 114 tonne, well done to them. Not sure where the person who quoted 160 tonnes got that from, maybe I am missing something. Does the loading have to be the same on each axle of a car to help with balance and avoid derailments?

Has this solved the issue entirely or is there still some concern?

Forgive me if linking to external sites is disallowed, I am new here, but looking at this page https://anonw.com/2019/08/06/my-first-rides-in-a-class-755-train/ it seems to state that the whole train is 114 tonne, which to me is way off. The author of this page seems to off photographed the PP, PTSW and DMS2 but not the DMS and PTS. Is there any chance that the total unit weight inclusive of bogie weight maybe stated on either the unphotographed DMS or PTS? I know that on the 150/0 and 150/2 units used on my local line the indiviual car weights are stated on each plate, and then the total unit weight is stated on one of the driving cars. I did read somewhere that a 4 car unit is 160 tonne with the bogies, and 114 without.

I get what you're saying, and agree with you that we will just have to wait for the RAIB report. My knowledge of trains and their compatability with the electrical circuits is almost non existant, can anyone which such knowledge tell me if it is a major issue? What I mean by that it, if there is a compatability issue with the electrical circuits for the level crossings on the Cromer Line, is it a simple (ish) fix, or is it a major crisis situation that could cause significant problems and/or cost some serious money? It would of taken a massive balls up to have occured on either the part of NR, Stadler or GA for the trains not the be compatible with the electrical circuits, although anything is possible. Regarding the my axle load comments, they were not about the continuous contact between both the wheel and the rail head, but more about the fact that if the 4 car unit does weight 160 tonnes empty, and the driving car weighs 27 tonne, then that leaves 36 tonne out of 160 on driving wheels, therefor leading to a lot of wheelslip. This maybe fine for the GA route, but if they were bought by say SWR or GWR for their routes, only having 22.5% of the total weight avaliable for adhesion won't be good. I reckon that on any major gradients (1:37 Exeter St Davids to Exeter Central) these units would slip to a stand. Does anyone on this forum know how much a 4 car unit unit weighs in total and how much of that is on the two power bogies?

Interesting. Do you know if they ever did anything to solve/lessen the problem? The Exmouth branch, WoE line etc. are all my local lines so I am familiar with those routes but was not aware of this issue. Interms of weight on axles, the powercar has the higher loading - 27 tonnes on 2 axles apparently. I have come to the conclusion that the 114 tonnes I read by adding up all the weight plates on a 4 car unit does not include the bogies weight as someone on here has previously said that the total unit weight is quoted as 160 ish tonnes. So 114 without bogies and traction motors, 160 with bogies. I still don't know how much weight is on the four driven axles though.

Ah, when I said 144 tonnes, I mean't 114. 114 seems lightweight, 160 sounds about right to me. I did read somewhere that apparently the axle load for the driving bogies is 9 tonne, giving 36 tonnes total adhesive weight which isn't great really. Also, don't forget that a 3 car is more like a 3.5 and a 4 is more like a 4.5.

This is my first post so forgive me if am making any major mistakes but I have a question that I have half the answer too already, It's just the second half I can't find anywhere. What is the weight of the 3 and 4 car Class 755 units? I read somewhere (maybe here) that they weigh something stupid like 144 tonnes, which to me seems strangly light. However, I then read that apparently they weigh more like 160 tonnes. I only ask as only the bogies on the driving cars are powered therefor giving only 4 powered axles for both the 3 and 4 cars units. Does anyone know how much of the 160 tonne is on the powered axles? I wonder this because I saw someone suggest that they maybe good for London Waterloo to Exeter Services seeing as they could be fitted with third rail gear and of course already have diesel engines. Although with them only having 4 powered axles, I don't know how well they would manage on Exeter and Honiton Banks. Sorry to drone on, its just a question I have had for a while and can't find a solid answer too.