With this PSR campaign on the UP interstate trains have doubled in size. Used to be 2-3 loco, 70 cars ang maybe a DP loco. Now it’s like they combined two trains, 70 cars, 2 or 3 locos and another 60 cars. If the train breaks a coupler knuckle I see the spares are in a holder on the loco. Have read that the engineer stays up front to forward/reverse the train while the conductor takes a leisurely walk back to find and repair the knuckle. Never have never witnessed this repair task. (statistics say 11000 knuckle failures per year ,30 per day nationwide)
Wondering:

Does the conductor have to carry the new knuckle from the front end all the way back to the break-apart?
With the back half of the train in emergency and not going anywhere can the engineer move forward until the last car of the front section is at conductors spot. Whereupon conductor puts the new knuckle aboard and rides back the standing rear section to replace knuckle and couple up?
If that is s no-no does the conductor have a carrying strap or something to help tote the new knuckle (50 pounds?) ?
During bad weather does the crew call dispatcher for assistance?
Thanks for any input.
Cal-P