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GWR operating short 'HSTGTi' sets (see diagrams section for workings)

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43096

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My understanding is that HST engines HAVE to run at 1,500RPM or very close thereto, in order to produce 50 cycles for auxiliary purposes. The alternator for ETS being directly driven by the engine.

For a four pole alternator to produce 50 cycles it has to run at 1,500RPM.



This not the case for locomotives that produce DC for ETS.



On more modern traction, 50 cycle AC can be produced at any reasonable engine speed by means of an inverter, HSTs however predate the ready availability of large inverters.



Or am I mistaken in this.

As I posted immediately above, that is nonsense for HST power cars.

Modern locos with ETH capability (e.g. Class 68, GBRf 73/9s) take the train supply off the DC link: there is no separate ETH alternator. In the case of the 73/9s, the DC link is around 900V DC I believe.
 
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Emblematic

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My understanding is that HST engines HAVE to run at 1,500RPM or very close thereto, in order to produce 50 cycles for auxiliary purposes. The alternator for ETS being directly driven by the engine.
For a four pole alternator to produce 50 cycles it has to run at 1,500RPM.

This not the case for locomotives that produce DC for ETS.

On more modern traction, 50 cycle AC can be produced at any reasonable engine speed by means of an inverter, HSTs however predate the ready availability of large inverters.

Or am I mistaken in this.

You are assuming that the AC frequency needs to be constant. Equipment intended to be run from local generator sources (trains, ships, emergency equipment in hospitals, etc.) is designed to operate over a wider range of frequencies than those designed for public utility supplies. Resistive loads such as heating have no dependency on frequencies, inductive loads can just be regulated to take less power at higher frequencies (unregulated, power would rise with frequency.) In general, higher frequencies are easier to deal with than lower, as low frequencies require larger components - transformers, motors etc. - for the same power.
 

dmncf

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It's notable how quiet the topic of this thread has gone; no news updates; no photos of GWR's first completed Mark 3s. One wonders if work has been stopped.
 

takno

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Still happening, but the first batch of free HSTs is all going to the Scotrail project, and there isn't that much to show on that project yet
 

43096

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Still happening, but the first batch of free HSTs is all going to the Scotrail project, and there isn't that much to show on that project yet
First set is for XC, then should be a GWR set. After that the XC and ScotRail programmes take priority, with remaining GWR sets at the back of the queue.

Wabtec currently have one GWR, one XC and the first two ScotRail sets in works for conversion.
 

co-tr-paul

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Can I just point out that although OP, not really involved with the HSTGTi's so news is not always obtainable by myself. We shall of course be working on them here once entered service.
 

43025 Exeter

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The fleet comprises Power Cars 43005/016/024/040-042/092-094/097/098/122/153-155/158/170/186-189/192/194/198 and Trailer Cars 48101, 48102, 48111 and 49101 at 23 Oct 2017. More Trailer Cars are being added - 42102 and 44079 have transferred from Porterbrook to First Group, 42103 and 42302 have transferred from First Group to Porterbrook. The Power Cars carrying green are 43005, 43016, 43041, 43093, 43187, 43188, 43194 and 43198. The renumbered vehicles are:
48101 ex 42168
48102 ex 42177
48111 ex 42093
49101 ex 44055
 

Techniquest

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Just when I thought I had nearly got them all for the umpteenth time! Only just got 40102 scored yesterday, before the 425xx and 460xx trailers I had almost the entire lot travelled in!
 

Wilts Wanderer

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Current projections are that the GWR set will not be ready for the January timetable change, a Sprinter will cover the intended diagram until whenever it makes an appearance.
 

Unclepete

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Hi,
Any further news on status of this first modified set being released yet?
As the ablove poster is suggesting January, just wondered if there was an expected release date?

thanks,
 

mic505

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First modified Scotrail set is due for release February 2018, so I would assume the XC set should be released between now and February 2018, hopefully. Maybe further complications has arisen with the XC coaches. I know there are differences between a loco-hauled MK3 coach and passenger MK3 coach. In my view I would do the XC then Scotrail sets in order of prority. Once the XC ones are done then move onto the GWR sets.
 

D2007wsm

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GWR in extra need of extra stock on the local services as much as any other operator. The peak services around Bristol can be horrendous, particularly between Bristol and Cardiff, these short HSTs can't come quick enough to supplement Turbo cascades.
 

TT-ONR-NRN

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Are we to get an interior refurbishment for these “Castles”?

I assume they will receive the same interior treatment as the refurbished GWR HSTs?
 

Starmill

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I'd expect the IC3000s to stay, which will probably make them the nicest regional express stock in the country :)

Regional express? The intercity trains will be XC and 80x. The 'interregional' trains will mostly be Turbos. What do you mean by 'express'?
 

XCTurbostar

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“Castles”..? That’s original. I would have laughed if they were called HST GTis in that magazine :D
 

47802

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Are these going to operate all-stations stopping services, then?

I wouldn't describe them as regional express but a longer distance regional train, isn't the plan for them to operate Penzance to Plymouth/Exeter and some Bristol-Exeter/Plymouth, so they might not be literally all stations stopper all the time but they will be more of a stopper than the IC services on those routes, as they are really a 2x158 substitute you could argue they are better than a 158, although probably a lot more expensive to operate.

The Scotrail versions well I suspect some would describe them as regional express others as Inter-City:rolleyes:
 
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brel york

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First modified Scotrail set is due for release February 2018, so I would assume the XC set should be released between now and February 2018, hopefully. Maybe further complications has arisen with the XC coaches. I know there are differences between a loco-hauled MK3 coach and passenger MK3 coach. In my view I would do the XC then Scotrail sets in order of prority. Once the XC ones are done then move onto the GWR sets.
The ex loco hauled xc vehicles were modified to run with hsts last time they were in Doncaster
 
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