Tram Trains thread

[Hook]

As I said ride quality covers many aspects of railway engineering- including comfort and is critical to the success or otherwise of the trial.

All can be measured quantitively and acceptable levels of ride quality must be obtained.

Simply put- ride quality effects costs and safety. Poor riding quality increases wear and so increases vehicle and track failure If poor ride quality cannot be designed out then the trial will end at the point where revenue falls or extra costs and/or safety limits are exceeded. There are countless examples of this in transport history.

 

The current Stagecoach operating franchise ends in 2024 and neither they or the owners have any obligation to run the new tram trains or route beyond the two year trial.

 

Wrong. Supertram, as previously mentioned, are contractually required to operate the service for five years.

 

It is also not a franchise, but a concession.

[Arthur Ritus]

Yes they are and you can here them coming from further away.

 

One of the most critical part of this trial are issues to do with all aspects of ride quality- which includes comfort.

Tram tracks and tram tyres have a different shape to ones on the railway. Because of higher speeds and longer straight sections, ordinary trams begin to roll and pitch more, this is dangerous (Croydon) at junctions and causes expensive wear. On the railway a tram would roll and pitch even more as the wheel flanges are too shallow-it would be catastrophic.

To reduce the roll and pitch, speed restriction was the traditional solution. On tram train, suspension stiffness, electronic control, special frog and guard rails and tyre shape will be tested.

 

If they cannot get this bit right in terms of costs, comfort and safety the route will be scrapped and the trial will end. The new trams will be converted into tram only operation.

All the new tram trains have ordinary tram wheels which makes this observation worrisome.

Blackpool removed its most modern set of trams (1960's) from normal service for this and other problems The Advanced Passenger Train was abandoned for similar reasons in the 1980's -famously invited reporters felt seasick.

 

Tram wheel flanges are only a slightly smaller than train wheel flanges and cannot really be blamed for Croydon, 50mph around that tight a bend which should have been 12mph would have probably had the same effect if had got train wheels.

 

The tramtrain wheels have to have the same diameter and thickness around the outer rim area as tram wheels as they run in the bottom of the channel through points and crossings on road sections. They have a thicker width nearer the axle where clear of the channel to engage on the guides on railway section points which have had to be raised to work.

 

The "sea sickness" alleged by the reporters on the apt was more to do with the excessive alcohol and rich food they were given, to, well, help make them "happier" with the experience and was typically over indulged. Other tilting carriages based on its design have had no such complaints, helped not having the "made in Britain" label especially BR.

 

The new tramtrains are a lot heavier at 66.1t as opposed to the old trams at 46.5t which account for more noise and vibration but shouldn't make the ride less smooth. Perhaps some more development on the suspension or drive gear?

 

---------- Post added 24-01-2018 at 20:27 ----------

 

It will never be a very good true test as no voltage switch over will done, a crucial part really.

 

It would have been interesting to see a tram coast from leaving the 750vdc until picking up the 25kvac. I suppose the 25kv would be brought along the tram branch so far, possibly to a straight bit so if the tram got stuck between supplies at least it wouldn't have its nose sticking out onto a railway line.

 

I can just hear the tanoy " would all passengers please get off and give us a push", certainly wouldn't recommend the driver climbing on the roof and putting a couple of jumpleads on the overhead lines.

 

The have batteries perhaps they could move it the short distance required, any tram engineers know?

 

I doubt the 25kv gear will stay for long on the sheffield trams, who wants to pay to maintain something not used. First time the selection gear fails it will be bypassed as a temporary measure to be fixed as needed. Lets sell it now as new, we'll get more for it.

[BigAl1]

who wants to pay to maintain something not used

 

SYPTE with the dot matrix?

[julado]

who wants to pay to maintain something not used

 

SYPTE with the dot matrix?

 

Sorry, the above post is still undergoing testing.

[BigAl1]

Sorry, the above post is still undergoing testing.

 

Indeed it has for two and a half years now with absolutely no sign of it ever working

[Jeffrey Shaw]

Sorry, the above post is still undergoing testing.

Must be a second-class post.

[AlexAtkin]

I actually found it quite shocking how uncomfortable the tram train is, as ACTUAL trains have no such problem.

 

I think you notice it more though because they cheaped out on the seats. Somehow they seem to be even less comfortable than the really old stock trains which have similar amounts of padding.

 

Why is it we are going backwards in ride comfort? The buses are doing it too, switching from thick padded coach seats to wafer thin bum busters.

[hackey lad]

I actually found it quite shocking how uncomfortable the tram train is, as ACTUAL trains have no such problem.

 

I think you notice it more though because they cheaped out on the seats. Somehow they seem to be even less comfortable than the really old stock trains which have similar amounts of padding.

 

Why is it we are going backwards in ride comfort? The buses are doing it too, switching from thick padded coach seats to wafer thin bum busters.

 

Fully agree . They are bum numbers .

[BigAl1]

I actually found it quite shocking how uncomfortable the tram train is, as ACTUAL trains have no such problem.

 

I think you notice it more though because they cheaped out on the seats. Somehow they seem to be even less comfortable than the really old stock trains which have similar amounts of padding.

 

Why is it we are going backwards in ride comfort? The buses are doing it too, switching from thick padded coach seats to wafer thin bum busters.

 

They are cheaper and so they can get more seats in. Even on the grown up railway there is a lot of criticism of seating comfort as price is placed before comfort

[Bilge]

There should be less seats and more standing room (with flop down seats) near the doors. Then more pushchairs and disability vehicles could get in. At busy times it's hopeless for these passengers.