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Class 93 Tri-mode Loco

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Bald Rick

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anthony263 said:
Could it haul 5 mk4's and a DVT up the marches I wonder
Click to expand...

craigybagel said:
Thanks, good to know.

I'm still dubious. It's a very big power deficit on paper to overcome and the Marches is not a forgiving line for an underpowered loco.
Click to expand...

Put another way, could a Class 25 haul 5 Mk4’s and a DVT over the Marches. I rather think one could.

(The Class 93 has the same power on diesel only as a Class 25. But the Class 93 also has battery power on top, which I imagine could be a little like the Turbo Boost button in Knight Rider. Younger viewers may need to research this reference).
 
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craigybagel

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Bald Rick said:
Put another way, could a Class 25 haul 5 Mk4’s and a DVT over the Marches. I rather think one could.
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As someone who drives 67s along the Marches for a living, and knows how much they need to be thrashed to keep to time, I rather think not.
Bald Rick said:
(The Class 93 has the same power on diesel only as a Class 25. But the Class 93 also has battery power on top, which I imagine could be a little like the Turbo Boost button in Knight Rider. Younger viewers may need to research this reference).
Click to expand...
The battery would need to more than double the power provided by the diesel engine to match a 67, and it would need to be large enough to last for long periods of time.

We're not talking about 1 or 2 minute climbs with 10 minutes in between to charge the batteries; to give one example, from near sea level at St Julian's viaduct to the summit at Llanvihangel over 20 miles away, only about 3 miles is downhill. The rest is all uphill - and with 2 or 3 station calls along the way. And it's hardly the only hilly section on the line - it's pretty much continuous up or down all the way from Shrewsbury to Newport.

But as a child who grew up adoring Knight Rider, I'm not going to complain about that reference!
 
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ac6000cw

ac6000cw

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craigybagel said:
As someone who drives 67s along the Marches for a living, and knows how much they need to be thrashed to keep to time, I rather think not.
Click to expand...
craigybagel said:
The battery would need to more than double the power provided by the diesel engine to match a 67, and it would need to be large enough to last for long periods of time
Click to expand...
Bald Rick just said 'could a Class 25 haul' - not 'could it match the existing cl. 67-based schedules' ;).
 
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Richard Scott

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craigybagel said:
As someone who drives 67s along the Marches for a living, and knows how much they need to be thrashed to keep to time, I rather think not.

The battery would need to more than double the power provided by the diesel engine to match a 67, and it would need to be large enough to last for long periods of time.

We're not talking about 1 or 2 minute climbs with 10 minutes in between to charge the batteries; to give one example, from near sea level at St Julian's viaduct to the summit at Llanvihangel over 20 miles away, only about 3 miles is downhill. The rest is all uphill - and with 2 or 3 station calls along the way. And it's hardly the only hilly section on the line - it's pretty much continuous up or down all the way from Shrewsbury to Newport.

But as a child who grew up adoring Knight Rider, I'm not going to complain about that reference!
Click to expand...
The one thing that counts against a 67 is its rather high gearing, surely this doesn't help on this sort of route?
Having said that not suggesting that a 93 would keep up with one.
 
ac6000cw

ac6000cw

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On the climb out of Sheffield in the recent video, the 93 is doing about 31 mph (the 6 x Mk 3s take about 10s to pass the camera). After a few calculations, I think that's about right for a full power diesel+battery climb on a 1%-ish gradient with some ETS load, based on the TE curves in the Rail Engineer article.
 
bahnause

bahnause

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ac6000cw said:
On the climb out of Sheffield in the recent video, the 93 is doing about 31 mph (the 6 x Mk 3s take about 10s to pass the camera). After a few calculations, I think that's about right for a full power diesel+battery climb on a 1%-ish gradient with some ETS load, based on the TE curves in the Rail Engineer article.
Click to expand...
Class 93 traction effort:
RailEngineer

Class 67 traction effort:
Railtechnical
 
ac6000cw

ac6000cw

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bahnause said:
Class 93 traction effort:
RailEngineer

Class 67 traction effort:
Railtechnical
Click to expand...

Thanks for the 67 info.

Putting them side-by-side and approximately matching the scaling of the two graphs (40,000 lbf = 178kN):

Class 93 versus 67 TE.png

Ignoring any ETS power draw, basically up to around 20mph the 93 on diesel+battery can accelerate faster (it's got over twice the TE up to about 10mph, then the advantage tapers down to 20mph). Above 20mph the 67 wins due to its much higher diesel power. Of course on OHLE the 93 completely turns the tables in its favour through the whole speed range...
 
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craigybagel

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ac6000cw said:
Bald Rick just said 'could a Class 25 haul' - not 'could it match the existing cl. 67-based schedules' ;).
Click to expand...
Fair point :lol:
Richard Scott said:
The one thing that counts against a 67 is its rather high gearing, surely this doesn't help on this sort of route?
Having said that not suggesting that a 93 would keep up with one.
Click to expand...
It's certainly true that they're not great on stop start stuff - but they could climb hills quicker than anything else in the fleet until the 197s arrived.
ac6000cw said:
Thanks for the 67 info.

Putting them side-by-side and approximately matching the scaling of the two graphs (40,000 lbf = 178kN):

View attachment 159059

Ignoring any ETS power draw, basically up to around 20mph the 93 on diesel+battery can accelerate faster (it's got over twice the TE up to about 10mph, then the advantage tapers down to 20mph). Above 20mph the 67 wins due to its much higher diesel power.
Click to expand...
That is a fascinating read alright, and confirms my own suspicions. 67s are pretty poor at getting going, but they do start to fly above 30mph in what feels a like a relentless manner
ac6000cw said:
Of course on OHLE the 93 completely turns the tables in its favour through the whole speed range...
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True. It's just a pity we're so far behind the rest of Europe when it comes to electrified milage!
Unfortunately on the TfW network, the limits of electrification are too small to make up for the reduced performance of a 93 on the non electrified parts, especially as the paths between Crewe and Manchester are pretty constrained by other services.
 
Rail Quest

Rail Quest

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I've been low-key monitoring all the videos released of this loco on testing and these sounds are really intriguing me.

Here's a video of the loco running entirely on the batteries, hauling the same 6 carriage load out of Sheffield:

Now, when thats compared to videos shared prior of the loco on diesel and diesel/battery, the loud fan noises only seem to be present on the latter so I'm assuming the coolant fans that can be heard are only for the engine, not the batteries. If so, why does a loco with such a small engine need such noticeable coolant fans? On the videos that I've seen, these fans sound just as loud as a 91/92 though this could just be deceptive.

Of course, given how few clips are out there ATM, the coolant fans may be for the batteries as well and their behaviour is a bit sporadic, not sure.
 
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Richard Scott

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Rail Quest said:
I've been low-key monitoring all the videos released of this loco on testing and these sounds are really intriguing me.

Here's a video of the loco running entirely on the batteries, hauling the same 6 carriage load out of Sheffield:

Now, when thats compared to videos shared prior of the loco on diesel and diesel/battery, the loud fan noises only seem to be present on the latter so I'm assuming the coolant fans that can be heard are only for the engine, not the batteries. If so, why does a loco with such a small engine need such noticeable coolant fans? On the videos that I've seen, these fans sound just as loud as a 91/92 though this could just be deceptive.

Of course, given how few clips are out there ATM, the coolant fans may be for the batteries as well and their behaviour is a bit sporadic, not sure.
Click to expand...
The cooling system has to remove a lot of heat, even if the engine were 50% thermally efficient, which it won't be, the cooling system still has to lose 1200hp (about 900kW) or 900000 joules of energy per second at full power. Try and find a video of a 73 on diesel in the summer (with original EE engine), can guarantee fan will be running and is quite loud!
 
ac6000cw

ac6000cw

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Rail Quest said:
Now, when thats compared to videos shared prior of the loco on diesel and diesel/battery, the loud fan noises only seem to be present on the latter so I'm assuming the coolant fans that can be heard are only for the engine, not the batteries. If so, why does a loco with such a small engine need such noticeable coolant fans?
Click to expand...
I suspect that because of space limitations (there's a lot packed into a 93) the radiator cooling fans are relatively small but high airflow - which tends to make them noisy. As best as I can work out from an overhead video I've found, and the drawings on the Revolution Trains website, there are two fans on one side of the roof right above the large radiator ventilation grille on one bodyside at the 'diesel' end of the loco, with a smaller grille on the other bodyside prossibly being the engine air intake.

== Doublepost prevention - post automatically merged: ==

Richard Scott said:
The cooling system has to remove a lot of heat, even if the engine were 50% thermally efficient, which it won't be, the cooling system still has to lose 1200hp (about 900kW) or 900000 joules of energy per second at full power.
Click to expand...
Yes, exactly (although some of the waste heat is carried away in the exhaust gas).

As an example, look at the size of the radiators at the rear of large modern US freight diesels (with 'at the crankshaft' 4800hp engines), which have to deal with four times as much waste heat. I've seen them running at full power in dust-laden air (a wheat field was being harvested alongside the track) and there was a column of fast-moving hot air 40+ feet high above each radiator fan... (my video of it)
 
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Rail Quest

Rail Quest

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Richard Scott said:
The cooling system has to remove a lot of heat, even if the engine were 50% thermally efficient, which it won't be, the cooling system still has to lose 1200hp (about 900kW) or 900000 joules of energy per second at full power. Try and find a video of a 73 on diesel in the summer (with original EE engine), can guarantee fan will be running and is quite loud!
Click to expand...
ac6000cw said:
I suspect that because of space limitations (there's a lot packed into a 93) the radiator cooling fans are relatively small but high airflow - which tends to make them noisy. As best as I can work out from an overhead video I've found, and the drawings on the Revolution Trains website, there are two fans on one side of the roof right above the large radiator ventilation grille on one bodyside at the 'diesel' end of the loco, with a smaller grille on the other bodyside prossibly being the engine air intake.

== Doublepost prevention - post automatically merged: ==


Yes, exactly (although some of the waste heat is carried away in the exhaust gas).

As an example, look at the size of the radiators at the rear of large modern US freight diesels (with 'at the crankshaft' 4800hp engines), which have to deal with four times as much waste heat. I've seen them running at full power in dust-laden air (a wheat field was being harvested alongside the track) and there was a column of fast-moving hot air 40+ feet high above each radiator fan... (my video of it)
Click to expand...
Very interesting insights - thanks both!
 
Bob Price

Bob Price

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Just seen it go by the Wingfield web cam. Heading to Rail Live on the 19th and 20th would be my best guess.
 
DanNCL

DanNCL

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A 93 would be able to physically couple to a Mark 5A set. It would not be able to work push-pull with the Mark 5A DT. I’m unsure about door interlock.

All a bit irrelevant as there’s not any plans to use 93s with Mark 5As.
 
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800001

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Doomotron said:
There are no overhead wires at Rail Live. I assume they could have been coupled to them dead, but I don't really see the point anyway.
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There is a short stretch of OHL at Rail Live, near to where the 93 is parked, cant remember if over an actual line or just installed away from a track.
 
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Ianigsy

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I have a suspicion I passed this heading back to Worksop at Chesterfield at about 1825 last night. Interestingly 66651 headed through southbound about half an hour later.
 
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