what were some of the larger, more well known colliery companies whose wagons could be seen on the ECML

[Hatfield Shed]

... as his research has developed it has shown that wagons were not always routed the way you'd expect...

Would that include distinct differences between the loaded movement up to town, and the empty returns trains? That was something I suspected, a good example being the prominently branded (and this easily recognised) 'MOIRA' colliery wagons. Most probably came up loaded on the LMS, but any consigned to a customer on the East side of London might well be returned empty on the LNER.

[jwealleans]

I'd have to find the volume where he went through some highly detailed colliery records he'd turned up. IIRC it was details of repairs and wagons stopped which included their eventual destination. I think it was on the LMS, but it's a while since I read it.

[Norton Wood]

Thank you all for the help!

Will certainly mean a reasonable order from POW sides and some internet surfing will be required!
This Forum has been so helpful! I'm pleased to see people are happy to help and point you in the right direction!

I'll keep up with this post in case anything "New" comes up