General instructions governing equated tonnage
1. The equated tonnage of any train is determined by multiplying the number of cars in the train by the car factor and adding the result to the sum of the tare and contents.
Example: (1) 42 cars. Total gross weight 2100 tons Car Factor 10 × 42 cars = 420 Equated tons 2520 (2) 84 cars. Total gross weight 1680 tons Car Factor 10 × 84 cars = 840 Equated tons 2520
2. The car factor is an allowance frictional car resistance and varies on different subdivisions according to the ruling The principal being that on low gradients the frictional resistance is a higher proportion of the total resistance than on steeper gradients. By use of the factor the trainload is so adjusted that the resistance is the same for all trains of equated tonnage whether composed of fully loaded, partly loaded or empty cars
3. Established will be exceeded by 1% if by so doing another car can be handled In the train.
4. The equated ratings shown are "A" for fair weather. These ratings will be reduced as authorized by ratings "B" to "K" for temperature.
Tonnage reductions Temperatures: Weather condition modifications Rating: Reduction in tonnage: Above freezing (32° above) A Nil 32° above to 16° above (or bad rail) B 5% 15° " " zero C 10% Zero " 10° below D 15% 11° below " 20° " E 20% 21° " " 25° " F 25% 26° " " 30° " G 30% 31° " " 35° " H 35% 36° " " 40° " I 40% 41° " " 45° " J 45% 46° " " 50° " K 50%
The Chief Dispatcher will issue special instructions in case of storm or temperatures lower than those shown.
5. New engines or engines out of shops after receiving medium or heavy repairs will be loaded 20% light on first outward trip and 10% light on return trip. Locomotive Foreman will advise Train Dispatcher and Yardmaster in such cases.
6. Any necessary adjustment in ratings shown in tables will be made by the General Superintendent, Transportation.
7. When an engine of different capacity from those shown in the table is used, the proper equated tonnage will be arrived at by taking the rating of the engine with the closest percentage capacity, dividing this rating by its percentage capacity and multiplying the result by the percentage of capacity of the engine to be used.
Example:— To find the equated rating of a 38% engine; Published rating of 40% engine = 2500 tons Equated tonnage rating of 38% engine = 2500 × 38 ÷ 40 = 2375 Equated Tons.
8. To determine proper tonnage for pusher, doubleheader or helper engines, unless special rating is given, add to equated rating of the first engine 95% of the equated rating in effect for each class of helper.
9. In making up trains, weight must be obtained by taking tare and contents from the waybill. When tare weights are not available, they will be estimated, the following weights to be used as a guide:
Passenger cars—4 wheel trucks 40 tons Passenger cars—6 wheel trucks (Baggage, Colonist and Coach) 70 tons Passenger cars—6 wheel trucks (Tourist, Sleepers, etc.) 87 tons Express Refrigerator cars 40 tons Freight 30 tons Steel automobile and box cars 25 tons Steel frame automobile and box cars 21 tons Wooden frame automobile and box cars 18 tons Stock cars 18 tons Hopper cars 24 tons General service 23 tons Steel and steel frame gondola cars 27 tons Steel underframe gondola cars 20 tons Hart convertible 21 tons Flat cars 18 tons Depressed flat cars 28 tons Caboose or van 20 tons
Agents will see that tare weight of all cars loaded in their territory is shown on the waybill in the space provided for it. This tare weight to be obtained from the actual inspection of the car and not to be estimated. In the case of cars not loaded at blind sidings, the conductor lifting car will make a note of the tare weight and see that same is properly entered on waybill.
10. In computing tonnage, fully loaded cars of grain, coal, rails, lumber, pulpwood, ties, etc., where weights are not given on the waybill, will be considered as carrying the marked carrying capacity of the car.
11. When dead engines are included in a train, four times the car factor will be added to the actual weight of each engine. Weights of engines being hauled dead are to be taken as under:
65% to 51% engines — 175 tons 30% to 21% engines — 100 tons 50% to 41% " — 150 " 20% to 15% " — 75 " 40% to 31% " — 125 " Below 15% " " 50 "
Example: Established rating 3000 equated tons Car factor 10 50 cars gross weight 2070 tons 2-53% dead engs. gross weight 350 tons Car factor 10 × 58 580 Equated tonnage 3000
12. The ratings given in the rating table are for the ruling grade; excess tonnage will be handled when it is to be set out short of or picked up beyond the ruling grade.
13. When an engine is unable to handle the authorized rating, a joint message, signed by Conductor and Engineer will be sent to the Chief Dispatcher, advising the reduction made and giving the reason to the same.
14. Yardmasters and Conductors will be held responsible for their trains being loaded to full authorized rating when tonnage is available.
CNR.CR.SOD.BD.90, p. 17