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Question: Would you welcome new class 278 trains?  (Voting closed: December 03, 2014, 11:21:24 AM)
Yes, they would be good on my line - 4 (7%)
Yes, if it meant more capacity - 16 (28.1%)
Yes, if it meant more services - 12 (21.1%)
Yes, in the right places - 15 (26.3%)
Yes, but not on my line - 4 (7%)
No - 6 (10.5%)
Total Voters: 28

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Author Topic: New trains from old?  (Read 20421 times)
grahame
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« Reply #120 on: February 09, 2017, 09:04:36 AM »

Power to weight ratios are (kW/t): electric 7.1, diesel 2.9, heritage DMU: 2.7 (1 motor car, 80% transmission).

For comparative purposes, what is the ratio for a more modern diesel (turbo, sprinter or pacer?)

For a predominantly electric service with a diesel offshoot, I guess 2.9 may not be too bad. Southampton stopper to Swanage, anyone?  And dare I mention Reading to Bedwyn?
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onthecushions
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« Reply #121 on: February 09, 2017, 01:03:21 PM »


I've calculated the following kW/t figures from power at rail (kW at c80%) and unit or car mass (t)

150: 4.8
159: 6.3
166: 5.2
170: 5.6
101: 3.1
180: 8.6
220: 9.3

The transmission losses don't have a uniform effect. The 101, having a gearbox, can't exert its full power continuously, unlike a unit with an electric or hydraulic power train. The advantage of a bigger engine is clear. The 560kW Cummins QSK19 is the reason than the adelantes and voyagers perform well; also they can have an engine for each car, the 319/4 has two per four car set. The 319 might go a little better if its engine management system allowed use of its short term ratings, i.e overloading the engine with maintenance and service life consequences.

In the end we come back to the fact that railways with lots of traffic, lots of stops, lots of hills and lots of high speed need electrification but that an auxiliary diesel is superb for rural rambles, for reaching the ends of branches and for getting home on a bad day. Hope this helps.

E&OE

OTC
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Four Track, Now!
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« Reply #122 on: February 11, 2017, 11:55:26 PM »

A possible threat to new trains from old is new trains in the form of the Very Light Rail vehicle. See Warwick University's website on the project. Today's Times reports that trials could start within 18 months, so around 2020 probably. These lightweight trains with lorry engines and a maximum speed of 50 to 70 mph are intended to be used on quiet branch lines, including reopened Beeching victims.

Sadly, Portishead is shown on the map that accompanies the article - sadly because it needs heavy trains to run to Parkway, Bath, Severn Beach etc.
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eightf48544
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« Reply #123 on: February 12, 2017, 01:21:52 AM »


Sadly, Portishead is shown on the map that accompanies the article - sadly because it needs heavy trains to run to Parkway, Bath, Severn Beach etc.

Or tram trains with street running through Bristol.
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grahame
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« Reply #124 on: March 03, 2017, 03:31:21 PM »

I saw a D-Train in action today - respondent in Silver with Red and Blue bits, running between Gloucester Road and Earls Court.

Oh ... wait ... I think that was the electric variant!
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grahame
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« Reply #125 on: May 18, 2017, 10:35:19 PM »

http://www.railtechnologymagazine.com/The-Sleepers-Daily-Blog/vivarail-d-trains-now-ready-for-sale-

Quote
Vivarail: D-Trains now ready for sale

Vivarail has announced that its first two production D-Trains are ready for sale, with delivery likely to be completed in early 2018.

The trains can be built and delivered ahead of the forecast schedule due to increased production capacity as Vivarail scale up for 2017 and beyond.

Preparation for construction is already underway at the Quinton Rail Technology Centre. The carriages can be supplied as either two or three car units with or without UAT.
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Richard Fairhurst
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« Reply #126 on: May 19, 2017, 10:30:24 AM »

Ah, I see Vivarail are now marketing their Unpredictable Ablaze Traction feature as an optional extra.

"No, we said passengers may alight here. Not 'the train should set itself alight'..."
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