Richard Armstrong said:Class 313 means the scream We will no longer have this sound:
FGWFan said:Agreed, 004 and 009 sound great. 004 is the star of my avatar too, it looks so very fine, it's my SHP of the month. Stratch that, it's my SHP of the year! To think that came out of my digi cam too. I'd have expected that to be the result of use of my mum's SLR. Pity I didn't phot it in a higher resolution though.
Still, 43025 sounded excellent recently, and it was only moving off a signal check outside Newport! Thrashtastic action from the Valenta!
ChrisCooper said:It's the Napier Turbocharger that provides the scream. They arn't unique to HSTs, also being fitted to a lot of English Electric engined locos, incluing the 20s and 40s (both well known for whistling) and also the 73s and Thumpers, aswell as the 56s (they actually sound very similar to HSTs). The high revs and high exahaust speed of the HSTs though means that the Turbo is turning very fast, hence the loud scream. The clagging of HSTs is also down to the Turbo, since being large it has quite a lag, so before it gets up to speed their isn't enough air getting into the engine to burn the fuel cleanly. The VP185 at least uses a number of smaller turbochargers, which actually scream more (higher pitch), but are much quieter, and have much less lag, so they don't clag as much. I'm not sure what the turbos on the MTUs are like. The other scream from HSTs, although really it's more of a high pitched whine, is from the cooling fan when that is running.
Yes, you all are correct
and yes HSTFan, the HST have had the screm from building!
Very informed Chris. I beleive the MTU engines use 4 turbo chargers. Apprently, the VP185 has 6! , hence its relitive quitenss!
The only engine that i never saw a HST fitted with and am quite interested in is the Mirless Blackstone engines that where trail fitted to a few Powercars (4 IIRC) in the 80s/90s. If anyone has info on those, id be very appreciative!
dvn1357 said:43167-43170 experimentally re-engined in 1987-1996 with Mirrlees Blackstone MB190
dvn1357 said:Mirrlees Blackstone MB190 - 2,400hp (1,788kW) at 1,500rpm
MB190 - 7 1/2in (190mm)
MB190 - 8 1/4in (210mm)
Info gathered from the Railway Centre (http://www.therailwaycentre.com)
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Just found some info here: