Lenny,

Here is the excerpt from National Perishable Protective Tariff #11 from 1941 about salting normal refrigerator cars:

(F) Shipper must specify in writing on shipping order and bill
of lading salting service desired, as provided in this rule,
using the appropriate, "Shipper's Instructions" as shown
below, and Agent must waybill accordingly:
(a) Salt Service with Standard Refrigeration Service:
1-"...% salt supplied with initial icing. No further
salting."
2-". . .%salt supplied with initial icing. Supply %
salt at all regular icing stations."
3-"...% salt supplied with initial icing. Supply same
percentage salt at (Specify regular icing station).
No further salting."
4- "Supply . . .% salt at (Insert first reicing station)
on basis bunker capacity of car and at all reicing stations
thereafter ... % salt on basis amount ice supplied . '
5-"No salt supplied with initial icing. Supply. . .% salt
at (Specify regular icing station) on basis bunker
capacity of car. No further salting."
6-"No salt supplied with initial icing. Supply. . .% salt
at (Specify regular icing station) on basis bunker capacity
of car and at (Specify regular icing station) on basis
amount ice supplied. No further salting."
7-"100 pounds salt supplied with initial icing. Supply
pounds (Specify 75 lbs. or less) of salt at each
regular icing station in transit."
Exception.—Not applicable on traffic covered by
paragraph G-9.
8-"No salt supplied with initial icing. Supply 100 pounds
salt at (Specify regular icing station) and pounds
(Specify 75 lbs. or less) of salt at each regular icing
station in transit."
Exception.—Not applicable on traffic covered by
paragraph G-9.
9-Applies only as provided in sub-paragraph 9 of paragraph
G.—"Supply. . . .pounds of salt at origin and. . . .
pounds at all regular icing stations."
Note.—-One of instructions provided above for supplying
salt on basis of percentage of ice supplied
may be given in addition to this instruction.
10-Applies only as provided in sub-paragraph 9 of paragraph
G.—"Supply. . . .pounds of salt at
(Specify origin and /or one or more regular icing stations
and quantity} of salt to be supplied at each)."
Note.—One of instructions provided above for supplying
salt on basis of percentage of ice supplied
may be given in addition to this instruction.

So it seems like the shipper specified the amount of salt as there was a charge for salt each time it was done. Is this different than when you worked for Western Fruit Express?

Bill Hirt