HST - Throttle Notch 5

[Ghawk2005]

Hi everyone

for any castle set HST drivers or knowledge of the aforementioned - does anyone know roughly what speed (as a minimum ) it is ok to go into full power after pulling away. From what I have witnessed, it seems to be around 15mph or more but this is only a rough guess using my gps speed app on my phone. Would be interested to know if there were any guidelines / minimum etc etc.

thank you

 

[irish_rail]

Hi everyone

for any castle set HST drivers or knowledge of the aforementioned - does anyone know roughly what speed (as a minimum ) it is ok to go into full power after pulling away. From what I have witnessed, it seems to be around 15mph or more but this is only a rough guess using my gps speed app on my phone. Would be interested to know if there were any guidelines / minimum etc etc.

thank you

No official guidelines, its pretty discretionary, but going into notch 5 , too quick on a downhill gradient will usually result in the speedometer losing its way somewhat.

 

[Ghawk2005]

No official guidelines, its pretty discretionary, but going into notch 5 , too quick on a downhill gradient will usually result in the speedometer losing its way somewhat.

Thanks
just thought there might be a limitation like the old days regarding the amps / overload etc

 

[irish_rail]

Thanks
just thought there might be a limitation like the old days regarding the amps / overload etc

The MTU computer (MDEC) won't allow too much power to be taken.

 

[Ghawk2005]

The MTU computer (MDEC) won't allow too much power to be taken.

Ah that makes sense. Thanks for your help

 

[Pugland53]

When I learned to drive HST’s I was told not to use notch 5 until the rear power car had cleared the platform. That was the full length HST’s, not the castle class. I do still get to drive the castles occasionally.

 

[Halish Railway]

When I learned to drive HST’s I was told not to use notch 5 until the rear power car had cleared the platform. That was the full length HST’s, not the castle class. I do still get to drive the castles occasionally.

That’s quite interesting - I had heard about that but I would have thought that that would have been from the days of Valenta engines & until more recently VP-185s to prevent blasting peoples’ ears out.

I would have imagined that the guidance on LNER’s HSTs would have been different once they were all fitted with MTU engines due to the 9 carriage length adding weight and slowing down acceleration, correct me if I’m wrong.

 

[hexagon789]

That’s quite interesting - I had heard about that but I would have thought that that would have been from the days of Valenta engines & until more recently VP-185s to prevent blasting peoples’ ears out.

I would have imagined that the guidance on LNER’s HSTs would have been different once they were all fitted with MTU engines due to the 9 carriage length adding weight and slowing down acceleration, correct me if I’m wrong.

I understood that was an FGW/GWR specific policy.

 

[paulkidger]

That’s quite interesting - I had heard about that but I would have thought that that would have been from the days of Valenta engines & until more recently VP-185s to prevent blasting peoples’ ears out.

I would have imagined that the guidance on LNER’s HSTs would have been different once they were all fitted with MTU engines due to the 9 carriage length adding weight and slowing down acceleration, correct me if I’m wrong.

As one not having intimate railway knowledge, I would have thought that electrical considerations (starting currents etc) were just as important as sudden loading of the prime mover and therefore only partly attributable to the engine maker. I imagine that the MTU control unit was programmed to avoid a sudden increase in load which would have caused smoke formation (and probably lots of other undesirable effects). I remember listening to the class 47 at my local station and there was a distinct pause after the initial start ..presumably to let the currents settle down after the initial starting inrush.

 

[hexagon789]

I remember listening to the class 47 at my local station and there was a distinct pause after the initial start ..presumably to let the currents settle down after the initial starting inrush.

I always understood that was the turbo lag or something like that (I've seen an explanation somewhere around) ; there is nothing to stop a 47 being opened up fully from a stand - indeed the BR driving instructions for most Diesel Electrics (Class 50s and unrefurbished 37s being two notable exceptions) say they should be opened up fully if possible.

Certainly on the E&G push-pulls, straight to full/('4' in the DBSO) was the usual method employed.