When CN runs a unit through Marshfield, WI…
The unit has 3 Locomotive pulling, and 1 Locomoitive pushing, how many Engineers are required?
Presuming that the CN is using Distributed Power for the pusher - One Engineer.
To expand on Balt’s answer - a number of locomotives can be connected (MU’d or multiple unit) so they operate as one.
This is actually how the early F units were designed to work - an A and B unit were originally connected with a drawbar.
There are limitations on how many locomotives can work together. I’ll let someone else address that, if you like. Back in the day it was not unusual to see a half dozen locomotives all together, all on line. Nowadays, if you see more than two or three, the rest will likely just be along for the ride.
As Balt notes - if the train is using distributed power (DPU), the engineer in the lead unit controls the rear (or mid-train) units via radio.
If the unit on the rear was added as a helper for some short grade (there are still some few helper districts), it will have its own engineer.
With the mention of helpers comes another question: Is there a second man on a helper who uncouples the helper when its task is done? If so, is he a brakeman?
On CSX there is a brakeman that is on the Helper crew. He is not designated as a Conductor. In Helper Districts, a device known as a ‘Helper Link’ permits Helpers to cut off on the fly. With Helper Link the air connection between the train and the helper is a electronic one. Air on the train is handled by the Engineer on the lead locomotive. Without Helper Link, the train must be stopped and anglecocks turned to allow separation without placing the train in emergency, as without Helper Link the Helper’s air line is physically connected to the train’s air line.
Thanks, Balt. I take that there is still a brakeman who puts the Link to work.
When I worked for Conrail we were only allowed to have 24 traction motors on line. Anymore than 24, it was feared, would put undue strain on knuckles and draw bars.
I’ve seen that limitation in the Special Instructions of Penn Central employee timetables. It was also stated that motors were not to be isolated to get down to that number.
CSX Helper Instructions - between Cumberland & Grafton
[quote user=“CSX Mountain Sub TTSI”]
- INSTRUCTIONS RELATING TO AIR BRAKE AND
TRAIN HANDLING RULES
5559 STEEP GRADE (1% OR MORE) TRAIN HANDLING - Unit Trains:
For head-end movement only, the allowable speed is 15
MPH while descending the following grades:
BA 207.8 and BA 223.0 - Seventeen Mile Grade
BA 242.3 and BA 252.3 - Cranberry Grade
BA 255.1 and BA 259.3 - Cheat River Grade
BA 262.0 and BA 267.4 - Newburg Grade - All Trains – If speed cannot be maintained at or below
the authorized speed for the train descending the
grades listed above:
A. The train must be stopped immediately by making an
emergency brake application of the air brakes including the
operation of the two-way EOT emergency toggle switch.
B. The train dispatcher must be contacted.
C. After stopping a minimum of 50% of train hand brakes
must be applied before the recharging procedure is initiated.
D. The brake pipe must be recharged for a minimum of 20
minutes. The rear car air pressure must be within 5 PSI of
the pressure shown on the HTD when the head end of the
train began the descent.
E. After recharging the air brake system to the required rear
car air pressure, a 6 to 8 pounds brake pipe reduction must
be made. After the brake pipe exhaust ceases, each car will
be visually inspected to determine the brakes are applied,
piston travel is within standards and brake shoes are against
each wheel.
F. The train may proceed only after being authorized by the
Road Foreman of Engines or the Trainmaster. If needed,
hand brakes may be left on the train to supplement train air
brakes descending the remainder of the grade. To prevent
sliding of wheels, avoid leaving hand brakes on any empty
c