of such comparison; or, during the same period, may maintain such groupings of the mileage accounts hereby prescribed as may be desired for that purpose.

It is further ordered, That any such carrier or any receiver or operating trustee of any such carrier may, in addition to the mileage accounts hereby prescribed, keep any temporary or experimental accounts the purpose of which is to develop the efficiency of operations: Provided, however, That such temporary or experimental accounts shall not impair the integrity of any of the mileage accounts hereby prescribed; and that any such temporary or experimental accounts shall be open to inspection by the Commission. [7

It is further ordered, That July 1, 1907, be, and is hereby, fixed as the date on which said First Issue shall become effective. [8

INTRODUCTORY LETTER.

To Carriers:

Interstate Commerce Commission,
Division of Statistics and Accounts,
Washington, June 3, 1907.

This Classification of Locomotive-Miles, Car-Miles, and Train-Miles, with the text pertaining thereto, is issued in accordance with an order of the Interstate Commerce Commission, a copy of which will be found immediately preceding this letter. The rules which the Classification contains should be observed by carriers in the adjustment of all entries in operating expense, in operating revenue, or in any other accounts kept by them to which the rules pertain.

The Classification here promulgated was worked out at a conference with accredited representatives of the American Railway Association and of the Association of American Railway Accounting Officers, and, with a few minor exceptions, embodies the recommendations submitted by them. It may be proper to say that the arbitrary of six miles per hour for switching locomotives is accepted temporarily, pending an investigation the purpose of which is to determine whether or not this arbitrary conforms to the facts. This investigation will be undertaken by the Division of Statistics and Accounts in co-operation with a Subcommittee of the Committee on Statistical Inquiry of the American Railway Association.

HENRY C. ADAMS,

In charge of Statistics and Accounts. [9

*Numbers refer to folios in brackets on right-hand side of pages, which are inserted
to preserve page numbers of original issue.

TEXT OF CLASSIFICATION OF LOCOMOTIVE-MILES.

REVENUE SERVICE.

FREIGHT LOCOMOTIVE-MILES.

Includes miles run by locomotives between terminals or stations with freight trains, also, miles run by locomotives between terminals or stations, with or without cabooses, going for or returning from this service; miles run by locomotives while assisting freight trains either as pushers or double-headers; miles run while hauling the second cut of a freight train doubled over grades; miles run light by locomotives going to or returning from assisting freight trains, as pushers or double-headers; miles run light returning to train after having hauled the first cut of a freight train doubled over grades; miles run light by locomotive of a freight train to and from the next coaling station or water tank for coal or water; miles run light to pick up or assist a freight train at stations between train terminals; miles run to pick up and haul dead freight-train locomotives into terminals; also, miles run by locomotives coming from or going to enginehouses or turntables from freight-train service; provided, no miles be allowed for this latter service if the distance be one-half mile or less in one direction.

PASSENGER LOCOMOTIVE-MILES.

Includes miles run by locomotives between terminals or stations with passenger, mail, and express trains, also, miles run by locomotives going for or returning from this service; miles run by locomotives while assisting passenger, mail, and express trains either as pushers or double-headers; miles run light by locomotives going to or returning from assisting passenger trains, as pushers or double-headers; miles run light by locomotive of a passenger train to and from the next coaling station or water tank for coal or water; miles run light to pick up or assist a passenger train at stations between train terminals; miles run to pick up and haul dead passengertrain locomotives into terminals; also, miles run by locomotives coming from or going to enginehouses or turntables from passenger-train service; provided, no miles be allowed for this latter service if the distance be one-half mile or less in one direction. [12

MIXED LOCOMOTIVE-MILES.

Includes miles run by locomotives between terminals or stations with mixed trains, also, miles run by locomotives between terminals or stations, with or without cabooses or passenger-train cars, going for or returning from this service; miles run by locomotives while assisting mixed trains, either as pushers or double-headers; miles run while hauling the second cut of a mixed train doubled over grades; miles run light by locomotives going to or returning from assisting mixed trains, as pushers or double-headers; miles run light returning to train after having hauled the first cut of a mixed train doubled over grades; miles run light by mixed-train locomotive to and from the next coaling station or water tank for coal or water; miles run light to pick up or assist a mixed train at stations between train terminals; miles run to pick up and haul dead locomotives from mixed trains into terminals; also, miles run by locomotives coming from or going to enginehouses or turntables from mixed-train service; provided, no miles be allowed for this latter service if the distance be onehalf mile or less in one direction.

SPECIAL LOCOMOTIVE-MILES.

Includes miles run by locomotives in special revenue service, such as locomotives hauling chartered trains, paid for either on the basis of a rate per mile run or a lump sum for the train; circus and theatrical trains run under contracts calling for payments of specified amounts for transportation between designated stations; char

tered trains for the Federal or State Governments, carrying troops, munitions of war, camp outfits, etc.; miles run while assisting special-service trains, either as pushers or double-headers; miles run while hauling the second cut of a special-service train doubled over grades; miles run by locomotives between terminals or stations, with or without cabooses or passenger-train cars, going for or returning from special service; miles run light by locomotives going to or returning from assisting special-service trains, as pushers or double-headers; miles run light returning to train after having hauled the first cut of a special-service train doubled over grades; miles run light by locomotive of special-service train to and from the next coaling station or water tank for coal or water; miles run light to pick up or assist a special-service train at stations between train terminals; miles run to pick up and haul dead locomotives from special-service trains into terminals; also, miles run by locomotives coming from or going to enginehouses or turntables from special service; provided, no [13 miles be allowed for this latter service if the distance be one-half mile or less in one direction.

SWITCHING LOCOMOTIVE-MILES.

Includes miles allowed to locomotives while switching in yards (but not at shops for shop purposes), and allowed to train locomotives for performing switching service at terminals or way stations.

Note A.-Switching miles should be computed at the rate of 6 miles per hour for the actual time engaged in such service in excess of one hour at any one station.

Note B.-Miles run by switching locomotives helping trains out of terminals as well as miles run light returning to the yard after such service should be treated as "Freight," "Passenger," etc., according to the class of the train helped.

NONREVENUE SERVICE LOCOMOTIVE-MILES.

Includes miles run by locomotives in the different classes of service described under "Nonrevenue Service Train-Miles,'' and, in addition, trial trips of locomotives, to be computed as follows:

(a) In case of trains of the freight class or of the passenger class and trial trips of locomotives, locomotive-miles should be the actual miles run by the locomotives.

(b) In case of trains of the work class the following rules should be applied: When orders are given to a work train to run to a certain point, to work between certain limits and return, the actual time-card mileage should be allowed between points named in the running order and, in addition, 6 miles per hour for time held between working limits. Work locomotives emploved for switching at shops for shop purposes, for spotting cars in gravel pits, working with pile drivers, etc., should be allowed a mileage of 6 miles per hour for the actual time in service.

RULES FOR COMPUTING LOCOMOTIVE-MILES.

1. All locomotive-miles made in hauling trains, except in helping and worktrain service, should be based on the actual distance run between terminals, to be computed from the official time table or distance table, as prescribed for train miles.

2. Helping miles of locomotives should be based on the actual distance made with trains in helping service or in doubling hills.

3. Work-train locomotive-miles should be computed according to the rules prescribed for work-train miles.

4. Light locomotive-miles should be based on the actual distance locomotives run light, or with only a caboose, for the entire distance between terminals. [14