UK freight trains

[Charlie B]

Nice to see the freight side of British operations - thanks for sharing.

these hoppers have knuckle couplers

What's the purpose of the second air line (if that's what it is)? Do these cars have air-operated hopper doors?

Wayne

Wayne, some of our heavy trains are using a second train line so the brake reservoirs can be kept fully charged, even when a reduction has been made. It is my understanding that it keeps full train line pressure at all times. Perhaps this is what this is.
Alan, thanks for posting the photos, I really enjoyed them. I wasn't aware that anything there was equipped with knuckle couplers.
Charlie.