is usually constructed to within 3 or 4 feet of its finished elevation, and is then completed by train. Banks constructed in this manner are remarkably solid and subsidence is unusual other than that arising in some cases from the compression of the original soil on which it rests; also the hay or straw on the levee has the advantage of protecting the newly made bank not only during the first year but subsequently as the seeds germinate and form a sod. The cost of the process varies with the local conditions, but this method is very satisfactory in that there is no interruption to traffic by work trains during the greater part of the work. This method has been largely used on the Northern Pacific Railway.

Photographs of actual working conditions received from E. F. Gorman and C. W. McFarland.

Bibliography

REPORT OF E. H. MCHENRY, Chief Engineer, Northern Pacific Railway, dated August 14, 1899. This report relates to filling bridges by sluicing. Similar report of November 30, 1896.

O. E. S. BULLETIN No. 249, Part 1, by Samuel Fortier, Chief of Irrigation, Department of Agriculture, pages 74 and 77, inclusive, dealing with filling of bridges on the Northern Pacific Railway, by hydraulics in the Cascade Mountains, Washington, between 1890 and 1897. THE 1920 REPORT of the American Bridge and Building Association, on Maintenance of Bridges during Filling, pp. 149 to 162, inclusive. ARTICLE in the Engineering News-Record of January 20, 1921, descriptive of filling by dumping from cars and spreading by sluicing, as practiced recently on the Minneapolis, St. Paul and Sault Ste. Marie Railway.

ARTICLE in the Engineering News-Record, January 16, 1921, descriptive of filling of high iron and steel viaducts and the preparation of the same to withstand the unusual stresses set up in the structures during filling operations and the methods whereby such difficulties may be lessened and in many cases overcome. This article by P. S. Baker, Engineer Bridges and Buildings, is descriptive of work of this character on the Philadelphia & Reading Railway.

(6) THE RELATIVE ECONOMY AND ADVANTAGES OF VARIOUS METHODS OF DITCHING EARTH CUTS, CLEANING AND SHAPING ROADWAY DITCHES, ROADBED AND BALLAST SHOULDERS, WITH SPECIAL REFERENCE TO LABOR-SAVING DEVICES NOW IN USE, AND THE DEVELOPMENT OF MACHINERY FOR THIS PURPOSE

(10) METHODS OF PROVIDING OUTSIDE DITCHES FOR MAIN TRACK DRAINAGE WITHOUT UTILIZING THE MAIN TRACK FOR LOADING THE EXCAVATED MATERIAL

H. E. TYRRELL, Chairman.

W. H. PENFIELD, F. RINGER, Sub-Committee.

The Sub-Committee believes that these two subjects may be combined and properly considered together under the general term "Ditching." Ditching on different railroads is done under many varying conditions; using practically the same method, the unit costs for work of like character vary about as follows:

These figures are derived from data furnished by less than thirty per cent of the railroads which have furnished information for the use of the Committee, and while they may have some significance, they are of little value in drawing conclusions without a complete statement of the conditions under which each job was done, as well as direct information as to what items were included in the costs and the methods of measurement. In other words, there is not unit costs data available except on individual railroads, and each railroad has its data in such shape that comparisons may be made on its own line, but it is impossible to compare it with other lines.

If on two railroads using the same method the unit costs of similar work vary more than one hundred per cent, as the data indicates, it is evident that either the units were not obtained in the same manner or the conditions under which the work was done were entirely different, even taking into consideration difference in rates of pay.

In arriving at conclusions it is, therefore, not practical to make the unit costs data the basis of such conclusions, but it is possible to draw conclusions from the general information furnished and to cite from such information which method is most economical under several sets of varying conditions. It is believed that conclusions so drawn will be of more value in determining the method to be used in any particular case than unit costs figures based on unknown conditions which might be entirely different from the case in question.

Methods

(1) Company Forces: Section labor, extra gang labor, or other regular employes subject to the regular direction of the Supervisors or other corresponding subordinate officers, with or without work train.

(2) Station Men: Work done by hand labor with shovels and wheelbarrows under contract on yardage basis.

(3) Teams and scrapers on force account or yardage basis.

(4) Auxiliary track and small cars: Where width of cuts and roadway permits a narrow gauge track is laid through the cut and to the spoil banks permitting small cars to be handled either by man power, teams or small gasoline mule. This is done either by contract or with company forces.

(5) Spreader car equipped with wings for shaping ballast shoulders, roadbed shoulders, ditches and slopes: These machines must use the tracks and entail the use of a locomotive and train crew. The material which they handle being either pushed to the end of the cut or over the top.

(6) Ditching machines: Machines known under this designation are numerous, but for the purpose of this report all machines designed for, or adapted to, excavating material, loading it on cars, or carrying it from one point to another, are included. It is not intended to include spreader cars equipped with ditching attachments, or ditching equipment which is used in the nature of a plow; nor is it intended to include steam shovels.

The most widely known ditching machine is, no doubt, the steam ditcher. There are several types of this machine and they are generally operated in a work train, the machine being set on top of a flat car, the equipment consisting of ditching machine, one dump car located at each end of the machine, spreader car and locomotive. They are also arranged to work over a train of flat cars and load one after another, backing up as they load. They may, if work requires, be removed from their flat cars and operated without a locomotive as they are self-propelled.

Another type of ditching machine not so generally recognized as such is the locomotive crane equipped with a one or one and one-half cubic yard clam-shell bucket. This may be operated in a train with dump cars at either end or under its own power with or without cars. In either case two laborers are necessary to properly place bucket in order to cut a uniform ditch.

The third type of ditching machine could be classed as scoop ditchers and would include those machines which do not operate under their own power, but have scoops or buckets, usually operated by compressed air, and so arranged that they are filled by the movement of the train, and the material is either carried out of the cut in the scoops, or is loaded on flat cars by means of an auxiliary hoisting engine and cables.

CONCLUSIONS

(1) Good roadbed drainage is the foundation of economical track maintenance; therefore, the ditching of cuts is of great importance and should be carried out currently with the regular yearly maintenance program.

(2) Ditching, in ordinary material, may be subdivided into two principal classes:

Class "A"-Cuts not more than six feet deep in average open counter.

Class "B"-Cuts more than six feet deep.

Class "A"-Cuts Less Than Six Feet Deep

(3) Company forces: On lines where traffic is heavy and ditching is done currently the work can usually be done economically by company forces, the material being cast out of the cut and leveled back so as to prevent it from washing down into the ditches. This method may also be economical on lighter traffic lines, where cuts are isolated and the volume of material to be moved is comparatively small.

(4) Contract forces; station men; teams and scrapers: These methods are found to be economical on lines of heavy traffic where, on account of deferred maintenance or nature of material, the volume to be handled is large. These methods may also be used to advantage on lighter traffic lines where conditions are favorable. In all cases where material is deposited on top of the cuts it should be leveled back to prevent washing down into the ditches.

(5) Spreader cars equipped with wings for shaping ballast shoulders, roadbed shoulders, ditches and slopes: These machines may be used to advantage on lines of moderate traffic in ordinary material, but their use is not recommended on heavy traffic, single track, lines with frequent trains; nor is the use of other ditching machines recommended under similar conditions.

Class "B"-Cuts More Than Six Feet Deep

(6) Company forces provided with push cars and dump beds, wheelbarrows or trackbarrows. Loading and hauling out: This method will be found to be economical on heavy traffic lines, and also on lines with moderate traffic, where ditching machines are not available, or where the volume of material to be handled would not justify their use.

The use of work trains with hand labor is generally uneconomic, and is not recommended.

(7) Teams and scrapers on yardage basis: Where the character of material is suitable, and the volume to be handled comparatively large, teams and scrapers may be used to advantage under unit cost contract provided the cuts are of sufficient width to permit of safe operation.

(8) Auxiliary track and small cars: This method may be used economically on heavy traffic lines where operating tracks cannot be interfered with and where there is sufficient clearance, provided the haul is long and volume of material to be handled would justify the initial cost of the plant installation.

Ditching Machines

(9) There are a number of items and conditions which should be considered before undertaking work with ditching machines and their equipment-interest on investment, depreciation, upkeep, work train service and interruption to traffic are vital items which should not be overlooked. Equipment of this class has advantages which should also be taken into consideration. Ditching machines have a wide scope of operation; they will move large volumes of material in a comparatively short time; they make it practicable to utilize the material excavated for bank widening, trestle filling or other like work. The final consideration rela、 tive to use of ditching machines is the density of traffic or frequency of trains.

The use of steam ditchers and their equipment is recommended in work where the cuts are long and deep, or where the volume of material to be moved is great; or where the material is wet and difficult to handle by other methods. Their use is also recommended where cuts are resloped or widened to such a limited extent as not to justify the use of steam shovel. Under similar conditions they may be used for widening embankments. They are particularly efficient in removing small slides or other like emergencies where material is wet or hard to handle.

Locomotive cranes equipped with clam-shell buckets one to one and one-half cubic yards capacity can be used successfully in cleaning out cut ditches where it is desirable not to disturb the slopes and will produce a ditch of uniform width and depth without handling surplus material or requiring any redressing by hand. On account of the possibility of a considerably longer boom, this machine is more elastic in disposing of material, as it will even deposit material above grade on top of cut of medium depth. Under favorable circumstances it may be used without work train service, as it is self-propelling. Also, on account of the long boom, when equipped with orange peal bucket, this machine can be used to advantage in cleaning out coarse material from cross ditches.

Where, on account of long haul in disposing of material, it is necessary to load many cars before dumping ditching equipment is recommended which will operate over a series of flat cars with a proper mechanical device or plow for unloading.

There may be isolated cases where it is economical to use scoop ditchers, but it is believed the steam ditcher or the locomotive crane will accomplish the same results with a greater flexibility.

(10) Work incidental to ditching such as shaping roadbed and ballast shoulders is primarily hand work after the major work of ditching is complete, but by the use of spreader cars with proper attachments this work may be done at a cost that is comparatively very low and their use is recommended for these purposes when the nature of material will permit and where traffic conditions are not such as to prohibit such interference.