Performance of heavy freight locomotives (e.g. Class 66 hauling stone trains)

[Nottingham59]

I'm trying to understand the actual capabilities of heavy freight locomotives like the Class 66. Wikipedia suggests a starting tractive effort of 409kN, and 260kN continuous at 15mph. Are these figures achievable in practice? 409kN is 40 tonnes, which seems a lot for a locomotive with steel wheels that weighs 130 tonnes. It implies a coefficient of friction of around 25%.

What trailing load can a Class 66 haul uphill? Arithmetic suggests they could start 4000 tonnes up a 1% gradient. Is that achievable in practice? Do freight companies adjust trailing loads depending on leaf fall season?

And thinking of actual examples, what is the maximum weight for stone trains that run on the MML and what is the steepest (uphill) gradient that they encounter?

Thanks in advance for any insights.

EDIT: And similar questions for the Class 60 and Class 70, which I understand have higher tractive efforts.

 

[The Planner]

I'm trying to understand the actual capabilities of heavy freight locomotives like the Class 66. Wikipedia suggests a starting tractive effort of 409kN, and 260kN continuous at 15mph. Are these figures achievable in practice? 409kN is 40 tonnes, which seems a lot for a locomotive with steel wheels that weighs 130 tonnes. It implies a coefficient of friction of around 25%.

What trailing load can a Class 66 haul uphill? Arithmetic suggests they could start 4000 tonnes up a 1% gradient. Is that achievable in practice? Do freight companies adjust trailing loads depending on leaf fall season?

And thinking of actual examples, what is the maximum weight for stone trains that run on the MML and what is the steepest (uphill) gradient that they encounter?

Thanks in advance for any insights.

EDIT: And similar questions for the Class 60 and Class 70, which I understand have higher tractive efforts.

Are you looking for what the regional loads books say? They give the max trailing load on sections of routes by loco.

 

[Nottingham59]

Are you looking for what the regional loads books say? They give the max trailing load on sections of routes by loco.

That would be very helpful. Are they available online? For starters, I'd be interested to know what is the maximum trailing load over Shap (both directions), for a loco like a 60, 66 or 70.

EDIT: And somewhere flat, like Peterborough - Ely.

 

[The Planner]

That would be very helpful. Are they available online? For starters, I'd be interested to know what is the maximum trailing load over Shap (both directions), for a loco like a 60, 66 or 70.

EDIT: And somewhere flat, like Peterborough - Ely.

They are internal docs unless someone decides to share them.

Shap northbound is 2065 for a 60, 1980 for a 66/6 and 2050 for a 70. Southbound 2815 for a 60, 2695 for a 66/6 and 2795 for a 70.

Peterobrough to March West Jn is 5865 for a 60, 6025 for a 66/6 and 5890 for a 70. March East to Ely is 4045 for a 60, 4160 for a 66/6 and 4060 for a 70
Ely to March East is 5180 for a 60, 5325 for a 66/6 and 5200 for a 70. March West to Peterborough is 3640 for a 60, 3745 for 66/6 and 3655 for a 70.

There are plenty of other locations where the limits are higher than Peterborough Ely. The WCML south of Crewe for example.

 

[Nottingham59]

They are internal docs unless someone decides to share them.

Shap northbound is 2065 for a 60, 1980 for a 66/6 and 2050 for a 70. Southbound 2815 for a 60, 2695 for a 66/6 and 2795 for a 70.

Peterobrough to March West Jn is 5865 for a 60, 6025 for a 66/6 and 5890 for a 70. March East to Ely is 4045 for a 60, 4160 for a 66/6 and 4060 for a 70
Ely to March East is 5180 for a 60, 5325 for a 66/6 and 5200 for a 70. March West to Peterborough is 3640 for a 60, 3745 for 66/6 and 3655 for a 70.

There are plenty of other locations where the limits are higher than Peterborough Ely. The WCML south of Crewe for example.

Thank you. That's very helpful.

 

[Rail Quest]

Shap northbound is 2065 for a 60, 1980 for a 66/6 and 2050 for a 70. Southbound 2815 for a 60, 2695 for a 66/6 and 2795 for a 70.

That's interesting - how come the 70s are limited to hauling slightly less than the 60s up shape but then slightly more for the other regions? Given the 70s have higher starting tractive and their additional horsepower should surely negate the loss in continuous tractive effort from higher gearing?

 

[The Planner]

That's interesting - how come the 70s are limited to hauling slightly less than the 60s up shape but then slightly more for the other regions? Given the 70s have higher starting tractive and their additional horsepower should surely negate the loss in continuous tractive effort from higher gearing?

No idea. It is what is in the documents.