1310 off Worksop today 0Q59 to Castle Donington EMDC https://www.realtimetrains.co.uk/service/gb-nr:R25139/2024-08-30/detailed ...then tomorrow 5Q58 0937 to Old Dalby https://www.realtimetrains.co.uk/service/gb-nr:K18459/2024-08-31/detailed
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Class 93 Tri-mode Loco
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Trainman40083
Established Member
93001, 93002 and 37218. 93002 isn't registered yet, so won't show on systems.
Why Castle Donington? Are those paths not completely different?
I think it is where the stock for the testing was taken the other day
Trainman40083
Established Member
Presume that Mark 3 set again at Castle Donington
Completely forgot about the Mk3s
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On the move away from Worksop 16 minutes late.
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Bob Price
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Picture via Twitter here: https://x.com/holtona72/status/1829861084561301563?t=4mkagNOXoFFwvKtRXkIgHw&s=19
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And a better view on Threads with the 37 on the front with 001 https://www.threads.net/@arutlandph...QGztHUQTDLjLEXqwG8RZY8X3i0ybb_N4l0S4AZhO-xYdA
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And a better view on Threads with the 37 on the front with 001 https://www.threads.net/@arutlandph...QGztHUQTDLjLEXqwG8RZY8X3i0ybb_N4l0S4AZhO-xYdA
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Sonyman66
Member
Rail Quest
Member
I've come across this video of 93001/002 running on the overheads on the test track with some high speed running. Skip to 0:34 for the clips with audio, and 0:42 for the high speed running clip. Good stuff! As one might expect, the locos are barely audible on electric aside from the wisp of what sounds like cooler fans at full power.
110mph they were reaching on the stretch of track passing Widmerpool.
Starting from a couple of hundreds yards south of Old Dalby Village and accelerating to the high speeds Widmerpool section, coming to a stand at Plumtree.
Been told a loco light engine 0-100mph in 60seconds!
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Would have thought they were quicker than that, an OEBB Taurus does that in around 14-16 seconds.
Unless it was 16seconds and I miss heard
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That would be more likely, expect they have car like performance when running light engine.
Nottingham59
Established Member
A 100t locomotive at 110mph (50m/s) has a kinetic energy of 125MJ. So an 86t at 100mph is about (guessing) 90MJ.
4.6MW under the wires will deliver that energy in 20s.
Allowing for wind resistance, 60s could be about right. 16s wouldn't be possible.
The U Taurus might be able to do it, with 6.4MW output and a top speed of 230km/h
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Even allowing for wind resistance and frictional losses 60s still sounds way too long. Happy to be proved wrong, though.
GRALISTAIR
Established Member
Really good looking locos too. Thanks for posting.
Nottingham59
Established Member
You're right of course. I was assuming the the 110mph top speed of the 93 was its limited by wind, but that's not the case.
Thinking about it, an HST (2.8MW) had an absolute maximum speed of around 140mph. So the wind resistance of a train at 100mph will be about 1.4MW, as resistance varies with the square of the speed. That's a sizeable fraction of the 4MW available, but the 93 will still be accelerating strongly when it reached 100mph. So maybe 25s to 100mph? That's still faster than many cars.
I think people may be forgetting the much lower co-efficient of friction between a steel wheel and a steel rail when compared to a rubber tyre on asphalt.
Nottingham59
Established Member
It's only at low speeds that friction matters. Above around 20mph, it's the power per tonne that limits the acceleration.
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Won't matter much with a light engine either. Converse gives rail the ultimate advantage as less friction means less energy needed to reach same speed. I know not quite as simple as that.
ac6000cw
Established Member
For a 93 on OHLE, the transition point is around 30mph (see the TE graph here: https://www.railforums.co.uk/threads/class-93-tri-mode-loco.210779/page-33#post-6791682 )
If you are trying to calculate a theoretical 0-100mph time for a 93 on OHLE, 0-30 is constant acceleration (constant force) and 30-100 is constant power.
Calculating each part separately using 4.6 MW max short-term power and 290 kN max tractive effort, I think it's about 4s for 0-30mph + 17s for 30-100mph = 21s for 0-100mph. That's not accounting for any rolling or air resistance etc., so the 25s to 100mph you estimated earlier is in the right ball park I think.
A light Class 90 can do 0-60mph in just under 12s and 0-75mph in just over 17s
Nottingham59
Established Member
That sounds about right. 75mph has 9/16 of the kinetic energy of 100mph, so a 90 would take 30-35 seconds to get to 100, but then it's on 3.7MW on AC compared to 4.6MW for the 93.
ac6000cw
Established Member
Note the 90 has higher short-term rating than the 93 (5.86MW versus 4.6MW) - see post https://www.railforums.co.uk/threads/class-93-tri-mode-loco.210779/post-6536307 and following posts.
Nottingham59
Established Member
Every day you learn something new! I don't know if the 93 has a short term rating too? Or even if it can add battery boost to the AC.
ac6000cw
Established Member
According to hwl's post here - https://www.railforums.co.uk/threads/class-93-tri-mode-loco.210779/post-6536326 - the 93's 4.6MW rating is a short-term 'boost' rating (it's 4MW otherwise).
I suspect real-world performance of a 93 versus a 90 will be swings and roundabouts - the 93's modern traction system provides higher tractive effort at lower speeds, so better acceleration, but the 90's higher short-term power rating should give it an advantage at the higher end of the speed range.
Of course once the wires run out the 93 is 100% better than a 90...
(and including that off-wire capability is what compromises the rating under the wires due to overall weight and space limits).
Nottingham59
Established Member
Whatever the light engine performance, it will be interesting to see the results of any trials with a load. The stated Traction Effort of 290kN suggests an absolute maximum load of 2300t up a 1:80 gradient. But I wonder what safety margin is needed for real life train scheduling?
For me, the questions for the 93 design are:
For me, the questions for the 93 design are:
- How heavy a load can it reliably haul over Shap and Beattock, in icy rain, in leaf fall season?
- How quickly can it get a train of intermodals up the hill out of Felixstowe, i.e. without wires?
- How well it performs over the unelectrified final mile at freight terminals near electrified routes, such as Gateway?
- What its performance is like with an 1800t max weight intermodal on long unelectrified lines across flat county in the fens and Lincolnshire
- Is the claimed advantage in operating costs over the 66 achievable in real life?
D365
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It looks like the question has been asked. No response to that end as yet.
What do you mean?