Class 66 Wheelsets Question

[whhistle]

Never got my head around this and I think I'm mixing up stories here.

The Class 66 is undoubtfully a success.
I'm sure I read that Brush (who provided the 3 / 3 wheel bogies) wanted £1 million per set, which is why we haven't seen any other wheel sets like it since that loco, despite them being better and cleared on more routes than the Class 67?

Is this correct?

If not, why haven't we seen any bogie / wheel arrangements like the 66 recently?

 

[43096]

Never got my head around this and I think I'm mixing up stories here.

The Class 66 is undoubtfully a success.
I'm sure I read that Brush (who provided the 3 / 3 wheel bogies) wanted £1 million per set, which is why we haven't seen any other wheel sets like it since that loco, despite them being better and cleared on more routes than the Class 67?

Is this correct?

If not, why haven't we seen any bogie / wheel arrangements like the 66 recently?

I think you are missing a reference to Class 89 in there as it makes no sense without it.

 

[507 001]

The 66 bogies are a GM design and have absolutely nothing to do with Brush. They even have a GM logo stamped on the side.

The 67s were originally intended to be 125mph CO-CO locos, but at the time Brush were the only ones capable of supplying 125mph CO-CO bogies (as used on the class 89). They wanted a silly amount of money per bogie, so the decision was made to switch to a Bo-Bo arrangement instead.

 

[whhistle]

Was the 89 the only 125mph co-co arrangement?

 

[TRAX]

The 66 bogies are a GM design and have absolutely nothing to do with Brush. They even have a GM logo stamped on the side.

Yup, it’s purely a GM/EMD product, and is well used in the US.

 

[coppercapped]

Was the 89 the only 125mph co-co arrangement?

In the UK, yes. There have been 125mph/200kph Co-Co locomotives on the continent - the best known being the magnificent 103s of the German railways.

 

[43096]

In the UK, yes. There have been 125mph/200kph Co-Co locomotives on the continent - the best known being the magnificent 103s of the German railways.

And SNCF’s CC6500s of course.

 

[edwin_m]

Continental bogie designs are likely to infringe the British loading gauge, and making them fit involves tweaks to some of the bits and pieces that assure smooth running at high speeds. Think of all the trouble SIG had with the Mk4 coach bogies. So it was probably true that Brush had the only 125mph 6-wheel powered bogie for the British loading gauge - and this is probably still true considering that no such design has been produced since then by anyone. Of course American bogies probably don't fit either, but modifying a 75mph design is likely to be easier as the dynamics are that much less critical.

The 67 was being designed during the era when the decision makers at Railtrack didn't much understand railways, so they may have nodded through a Bo-Bo design without really being aware of issues such as axleload and track damage.

 

[CosherB]

Continental bogie designs are likely to infringe the British loading gauge, and making them fit involves tweaks to some of the bits and pieces that assure smooth running at high speeds. Think of all the trouble SIG had with the Mk4 coach bogies. So it was probably true that Brush had the only 125mph 6-wheel powered bogie for the British loading gauge - and this is probably still true considering that no such design has been produced since then by anyone. Of course American bogies probably don't fit either, but modifying a 75mph design is likely to be easier as the dynamics are that much less critical.

The 67 was being designed during the era when the decision makers at Railtrack didn't much understand railways, so they may have nodded through a Bo-Bo design without really being aware of issues such as axleload and track damage.

Other than axle load, how would the 67 have been materially different had it been a Co-Co?

 

[edwin_m]

Other than axle load, how would the 67 have been materially different had it been a Co-Co?

It would have had to be longer to accommodate the extra wheels, and therefore heavier. Might just have looked like a 66 with a more streamlined cab.