The British HST\XPT: Questions?

[Redshirt214]

What is the difference between conventional & HST coaches, and would the HST\XPT powercars be able to pull conventional equipment of the type Australia uses on it's luxury trains? Also, would you consider the HST a DMU, or a locomotive? Wiki says BR treated them like DMU's, but I'm not sure that's at all correct...

[mtuandrew]

To put it in American terms, the HST power cars are equivalent to the Acela or LRC power cars. That is, they would function perfectly well as locomotives in their own right, and with the right couplers they could pull any car, but they are designed specifically to be paired with a set of specialized Mark 3 cars. As for the coaches, here's what Wikipedia has to say:

The main difference between the HST vehicles and the loco-hauled Mark 3A relate to electrical supply arrangements. HST MK3 coaches take an industrial voltage/frequency 3-phase supply directly from an auxiliary alternator in the power car to supply on-board equipment such as air conditioning. The loco-hauled vehicles take a standard single-phase 1000 V AC or DC train heat supply from the locomotive and convert it through motor generator units located under the floor. These convert the train supply to 3-phase 415/240 V 50 Hz AC to power air conditioning and other ancillaries. This difference makes the two types non-interconnectable in service conditions. The other main difference is the lack of buffers on HST coaches.

Instead of the Mark 3 coach used in Britain, the XPT uses a variant of a Budd stainless steel coach. I can't recall the reasons Australia had for doing so, but if I squint, it looks like a string of Silverliner IIs or IIIs sandwiched between each power car. I like it!

[David Benton]

I'm sure the xpt does use the British mark 3 coach. It is the Australian long distance trains, such as the Indian Pacific that uses the Budd designed stock.
From memory, I think the hst coaches came before the loco hauled Mark 3's. in other words, the Mark 3 loco hauled coach is an adaption of the hst coach, not the other way around .

[David Benton]

Well, I'll have to eat my hat, the XPT coaches are from a budd design. They appear to be quite abit shorter than the BR Mark 3.
So for years (aprrox 1984 - 1990) I thought i had ridden in a Mark 3, when i hadn't.