LMS_LNER_SR_GWR_fan2004 Posted June 11, 2018 Share Posted June 11, 2018 Hi guys, I was train spotting at St Neots yesterday and an EMT hst came through and the engines had a squealing sound just like the old valentas. I them compared my footage with some older footage of them on YouTube and had the exact same sound. So, could this be a hst that has a valenta in it? If someone could help me that would be very helpful. Kind regards, Matthew Link to post Share on other sites More sharing options...
woodenhead Posted June 11, 2018 Share Posted June 11, 2018 EMT HSTs still have Paxman engines VP185. No production HST has a Paxman Valenta engine anymore. Link to post Share on other sites More sharing options...
LMS_LNER_SR_GWR_fan2004 Posted June 11, 2018 Author Share Posted June 11, 2018 Well, that says it then Link to post Share on other sites More sharing options...
woodenhead Posted June 12, 2018 Share Posted June 12, 2018 Well, that says it then I am told the EMT sounds a bit like the old HST but I doubt anything will ever sound like an original production HST again, even the prototype sounds more bus like. As to the engines that Cross Country, GWR and East Coast/Virgin East Coast/LNER (or whatever name it now goes by) use - I might as well be sat in a lorry park. Here's one for us all to remember how good they used to sound 12 1 Link to post Share on other sites More sharing options...
Andrew Young Posted June 12, 2018 Share Posted June 12, 2018 The EMT powercars sound nothing like the Valenta! They sound more like a rattly tractor. Sadly the MTU power plants of the XC/EC/GW power cars lack the scream of a Paxman Valenta. But the extra horsepower in them is appreciable when you’re driving them. Andrew 1 Link to post Share on other sites More sharing options...
DY444 Posted June 15, 2018 Share Posted June 15, 2018 (edited) The EMT powercars sound nothing like the Valenta! They sound more like a rattly tractor. Sadly the MTU power plants of the XC/EC/GW power cars lack the scream of a Paxman Valenta. But the extra horsepower in them is appreciable when you’re driving them. Andrew I was under the impression that the MTU engines were rated at 2250hp as per the Valentas due to concerns about the alternator/rectifier rating. Those concerns stemming from 43169's rectifier going up in smoke during the trials of the MB190 configured at 2400hp. Edited June 15, 2018 by DY444 Link to post Share on other sites More sharing options...
hexagon789 Posted June 15, 2018 Share Posted June 15, 2018 I was under the impression that the MTU engines were rated at 2250hp as per the Valentas due to concerns about the alternator/rectifier rating. Those concerns stemming from 43169's rectifier going up in smoke during the trials of the MB190 configured at 2400hp. You are correct, while capable of producing 2,700hp, the MTUs are down-rated to 2,250 for use in the HST sets. Besides even if they were still 2,700hp, the electrics couldn't take it and the traction motors are unchanged so you wouldn't get any more power-at-rail anyway. Link to post Share on other sites More sharing options...
RMweb Premium keefer Posted June 15, 2018 RMweb Premium Share Posted June 15, 2018 The fact they're down rated should have the added benefit of better engine reliability Link to post Share on other sites More sharing options...
RMweb Premium Davexoc Posted June 15, 2018 RMweb Premium Share Posted June 15, 2018 You are correct, while capable of producing 2,700hp, the MTUs are down-rated to 2,250 for use in the HST sets. Besides even if they were still 2,700hp, the electrics couldn't take it and the traction motors are unchanged so you wouldn't get any more power-at-rail anyway. While the engine is capable of 2700hp, if the sum total of the electrical equipment is less than 2700hp, then it is never loaded to that. The load on the engine varies depending on traction requirements, auxilary machines such as blowers, compressors, pumps and also train supply. The cooling system also adds a load onto the engine, but just because it is capable of 2700hp, if the maximum requirement is 2250hp, you had might as well derate it. The control is all down to the load regulation, not forgetting that the rear power car is normally producing ETS, so the front power car has power to spare. Dave Link to post Share on other sites More sharing options...
Hairy Bear Digital Posted June 15, 2018 Share Posted June 15, 2018 Both the vp's and mtu's are derated so that the maximum rpm is 1500.This is the maximum speed of the alternator. The amount of load of the auxiliaries / train supply has no bearing on the output of amps to the traction motors. These are separate windings on the alternator. Vp185 produces 2282hp at 1500rpm. Mtu in r41config for rail traction produces 2280hp at 1500rpm I believe. They both have significant more torque than the old valenta's, one of which can still be heard in the prototype power car. Link to post Share on other sites More sharing options...
RMweb Premium Reorte Posted June 16, 2018 RMweb Premium Share Posted June 16, 2018 I'm afraid that as a child I always used to put my hands over my ears every time one passed when we were waiting for our train. Link to post Share on other sites More sharing options...
45125 Posted June 16, 2018 Share Posted June 16, 2018 (edited) Both the vp's and mtu's are derated so that the maximum rpm is 1500.This is the maximum speed of the alternator. The amount of load of the auxiliaries / train supply has no bearing on the output of amps to the traction motors. These are separate windings on the alternator. Vp185 produces 2282hp at 1500rpm. Mtu in r41config for rail traction produces 2280hp at 1500rpm I believe. They both have significant more torque than the old valenta's, one of which can still be heard in the prototype power car. The MTU power unit is rated at around 2300hp, plus the cooler group does not draw any where the amount of power that a *rappy Marston cooler group did. The cooler group can suck nearly 200 hp off the engine........................ Edited June 16, 2018 by 45125 Link to post Share on other sites More sharing options...
E3109 Posted June 16, 2018 Share Posted June 16, 2018 (edited) A class 253 unit zinged past me earlier while I was looped, and TBH I wondered if they were still fitted with the original power plant. They sounded pretty decent for a unit. It was an EMT one, if that means anything. Also noticed an ECML set at Peteborough earlier, VT trailers sandwiched between two EMT power cars. Edited June 16, 2018 by E3109 Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted June 17, 2018 RMweb Premium Share Posted June 17, 2018 A class 253 unit zinged past me earlier while I was looped, and TBH I wondered if they were still fitted with the original power plant. They sounded pretty decent for a unit. It was an EMT one, if that means anything. Also noticed an ECML set at Peteborough earlier, VT trailers sandwiched between two EMT power cars. Post 2 seems to answer your question. Link to post Share on other sites More sharing options...
37501 Posted September 12, 2018 Share Posted September 12, 2018 I do miss the Valenta engined HSTs as they sounded great. Still they could be challenging to maintain. I worked as an HST fitter at Old Oak Common in 1991 and later encountered them in the Royal Navy where they were used as generators on Invincible class carriers and the Type 23 Frigates. The ones on the carriers were the larger 16 cylinder version with two turbos. The Type 23 used the 12 cylinder version similar to the HST. The ones on the 23s are still in service today but the carriers have gone. I always found them prone to oil, fuel and coolant leaks and impossible to keep clean. Seen several catastrophic failures with connecting rods snapping or valves shearing off and destroying piston crowns. Have changed most of the major components such as heads, pistons and liners with the engines in situ. Would have been useful to have 3 hands and fingers 12 inches long.... 3 Link to post Share on other sites More sharing options...
RMweb Gold The Fatadder Posted September 12, 2018 RMweb Gold Share Posted September 12, 2018 Did a Velentia (and associated electrical bits) get preserved when they were ripped out? Would be nice if when the HSTs finally get retired someone could restore one to original condition Link to post Share on other sites More sharing options...
Pete the Elaner Posted September 12, 2018 Share Posted September 12, 2018 Did a Velentia (and associated electrical bits) get preserved when they were ripped out? I believe the preserved prototype power car has one. Link to post Share on other sites More sharing options...
Wickham Green Posted September 12, 2018 Share Posted September 12, 2018 I'm afraid that as a child I always used to put my hands over my ears every time one passed when we were waiting for our train. I'm afraid that as a child the concept of an HST was way, way in the future ! Link to post Share on other sites More sharing options...
woodenhead Posted September 12, 2018 Share Posted September 12, 2018 Did a Velentia (and associated electrical bits) get preserved when they were ripped out? Would be nice if when the HSTs finally get retired someone could restore one to original condition That is the aim of the 125 Group - they have components for one just not a body yet but that could change soon with the IEPs - of course just because another train to revolutionise the railways has arrived it doesnt mean all the HSTs aren't still wanted. I believe the preserved prototype power car has one. They advertise it's screaming credentials on the 125 group page. http://www.125group.org.uk/ 1 Link to post Share on other sites More sharing options...
Classsix T Posted September 12, 2018 Share Posted September 12, 2018 Not sure if the alternator sets were kept, but iirc, the Valenta engine was purchased by the 125 Group for the princely sum of a whole one of our English pounds. As a member of the Class 56 Group, I'm hopelessly optimistic that GBRf will be as generous with the Ruston-Paxman lumps they'll bin for their Frankenstein Grids. When Dad worked in the print trade, he bought home proofs of Paxman's Valenta brochure, and later Ruston/GEC product literature, they always looked clean in them! C6T. Link to post Share on other sites More sharing options...
RMweb Gold russ p Posted September 12, 2018 RMweb Gold Share Posted September 12, 2018 The EMT VP185s don't sound too bad when flat out , not valenta thrash but so much better than that MTU shi£e I do wonder what an unsilenced MTU would sound like Link to post Share on other sites More sharing options...
Titan Posted September 12, 2018 Share Posted September 12, 2018 Just thinking, was the HST the only Paxman engined BR diesel that was a success? Link to post Share on other sites More sharing options...
45125 Posted September 15, 2018 Share Posted September 15, 2018 The EMT VP185s don't sound too bad when flat out , not valenta thrash but so much better than that MTU shi£e I do wonder what an unsilenced MTU would sound like They sound much the same with or with out the silencer. The Paxman pile of s***e sounds far better with out its silencer, most of the resonance that comes from the silencer goes. The Paxman heap is was horrible to work on with oil, fuel and coolant pissing everywhere . You never did oil changes on them as they used so much oil. Link to post Share on other sites More sharing options...
RMweb Gold russ p Posted September 15, 2018 RMweb Gold Share Posted September 15, 2018 They sound much the same with or with out the silencer. The Paxman pile of s***e sounds far better with out its silencer, most of the resonance that comes from the silencer goes. The Paxman heap is was horrible to work on with oil, fuel and coolant pissing everywhere . You never did oil changes on them as they used so much oil. Obviously you must work on HSTs but the MTUs have no character. I also think the 56 is one of the best drivers engine ever, but fitters absolutely hate the things. Link to post Share on other sites More sharing options...
Ken.W Posted September 19, 2018 Share Posted September 19, 2018 The control is all down to the load regulation, not forgetting that the rear power car is normally producing ETS, so the front power car has power to spare. The amount of load of the auxiliaries / train supply has no bearing on the output of amps to the traction motors. These are separate windings on the alternator. While the Electric Train Supply may be supplied by seperate windings on the alternator, it does still place a significant power load on the enging driving it, to the extent that the engine supplying ETS 'idles' at Notch 2 revs. Hence why it can be heard which engine is supplying the ETS. Although it's normal practice to run with ETS on the rear engine (with very good reason but that's another story), the ETS load is such that in event of a fault where an engine is unable to supply traction power but is still running, then it's standard practice for the ETS to be supplied from that engine if possible. And yes, there is a significant performance difference between a set with one engine suppying ETS only, and a set with only one engine running and supplying both traction power and ETS. I find the VP185 engined power cars hired in from EMT to be extreamly noisy, especially when standing idling in Kings X, you'd think they were running flat out! If I can be permitted to stray back briefly to the OP, lol, although not in passenger service, what engines do NR's NMT power cars have? Link to post Share on other sites More sharing options...
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