Rolling Stock Wheel Arrangements

[route:oxford]

Following on the from thread on Diesel Wheel Arrangements...

I was looking at the Car Transporters used by BMW at their Mini plant at Cowley the other day (Good view from Unipart Offices)

The transporters are made of up a 5 car articulated unit. There is a 3 axle Bogie at each end and same at each articulation(correct term?).

Is this style of unit fairly unique in the UK for either passenger or freight? I couldn't quite decide if the layout would improve or worsen track wear.

 

[starrymarkb]

Alstom proposed offset articulation for the Thameslink stock. But were rejected by the conservative* DfT




*Not politically speaking, more in the dictionary sense of "adverse to change or innovation"

 

[Kingfisher200262]

Following on the from thread on Diesel Wheel Arrangements...

I was looking at the Car Transporters used by BMW at their Mini plant at Cowley the other day (Good view from Unipart Offices)

The transporters are made of up a 5 car articulated unit. There is a 3 axle Bogie at each end and same at each articulation(correct term?).

Is this style of unit fairly unique in the UK for either passenger or freight? I couldn't quite decide if the layout would improve or worsen track wear.

In the late 19th and early 20th Century, several of the pre-grouping companies had six axle passenger coaches, to spread the weight on more axles when axle load limits were much lower than they are now.

I'm not sure whether it was the case for all companies, but the London & North Western Railway used a radial "steering" bogie to minimise track wear.

 

[jopsuk]

LNER had sets of four coaches that used "shared bogie" (rather than the the "offset" proposed in the rejected Thameslink poposal) articulation. At any stretch, the shared-bogie articulation is quite common in passenger stock abroad- it is popular for High Speed as one benifit is that it is far harder for derailed stock to "jack knife". For freight, it'll only be done where the mass/volume ratio of the cargo is such that axle loads are low anyway- though I'm curious as to what the specific advantages are for the car transporters.

 

[Royston Vasey]

LNER had sets of four coaches that used "shared bogie" (rather than the the "offset" proposed in the rejected Thameslink poposal) articulation. At any stretch, the shared-bogie articulation is quite common in passenger stock abroad- it is popular for High Speed as one benifit is that it is far harder for derailed stock to "jack knife". For freight, it'll only be done where the mass/volume ratio of the cargo is such that axle loads are low anyway- though I'm curious as to what the specific advantages are for the car transporters.

I would expect this is so vehicles can be driven through the train from the rear more easily, and to reduce the gaps needed to be left between cars in adjacent wagons, thus maximising capacity.

 

[mallard]

The Eurostars have "shared bogie" articulation, as did the APT's.

I think the major reason why it's never been common under BR and later is the added complication it creates when a vehicle needs to be removed/swapped/added from/to a formation.

 

[sprinterguy]

Knowing that vehicle articulation with two axle bogies is a common phenomenom internationally, one of the points of the original post that hasn't been answered is whether tri-axle articulated bogies are a common feature, as with the car transporters mentioned? Anyone spread any light on that?

The old 12 wheeler Pullman cars mentioned above, that were used by various pre-nationalisation railway companies to offer greater ride comfort, always look to be extremely impressive vehicles. Back home in Sunderland, we even have three of them down on the seafront, unfortunately no longer painted in Pullman umber and cream livery though.

Co-co wheel arrangements, I think cause greater track wear than Bo-bo wheel arrangements, although of course spread the vehicle weight over more axles so the track force per axle is reduced. In the case of the aforementioned car transporters I imagine that tri-axle articulated bogies cause less track wear than two individual bi-axle bogies at the end of each wagon, but the main benefit will be in maximising the length of vehicle floor space that can be used for cars. Are the car transporters on this particular run single or twin deck? I assume that tri-axle articulation is used as the axle load would be too great with a full compliment of cars loaded onto the wagon if they used bi-axle articulated bogies.