Popular Science Monthly 



55 



with is one of the most effective systems 

 ever devised. It is in use at three points 

 along the subway route in New York city. 

 It has made possible the employment of 

 huge fifteen-ton motor-tractor and trailer 

 units and has speeded up the entire 

 work of getting tiie excavated material 

 out of the ground. 



The system consists of an elevated 

 platform set up on wooden bents on 

 opposite sides of the street directly 

 adjacent to the shaft Icatling down into 

 the cut, an electric crane on top of this 

 platform, and a double-decked stand on 

 the street beneath it with 

 an adjustable draw- 

 bridge pivoted at 

 one end to a per- 

 manent bum- 

 per to 

 which 



SIX EMPTY CARS RUN OFF TRACTOR 

 BY GRAVITY BRIDGE LOWERED AS ' 

 SHOWN 



buckets are rolled down on it by gravity. 

 The free end of the drawbridge is then 

 raised to a level with the top of the 

 double-decked platform and the loaded 

 buckets run down it on tracks on to the 

 trailer, which is then ready to leave ior 

 the dump. 



This entire operation takes five min- 

 utes. By the old method it took 

 twenty-five minutes. The large saving 

 has been made i)\' having the load ready 

 when the vehicle returns to the platform. 

 The use of buckets with wheels has 

 made possible the quick loading on the 

 surface. They have also eliminated the 

 congestion at the shaft bottom when 

 ordinary buckets loaded on mine flat-- 

 cars were used because these, when 

 empty, had to be kept near the bottom 

 of the shaft until an empty bucket was 

 lowered from the motor \ehicle, mean- 

 time held idle. The new system has 

 reduced danger to a minimum and no 

 accidents have yet been directly 

 attributable to it. Thus speed and 

 safety have been combined in this 

 newest method of subway excavation . 



. ^ FOR GUIDANCE 

 M BACKING UP 



TRAILER WITM 

 6 CARS 2 ROWS 

 3 IN A ROW 



MOTOR TRACTOR 



Only five minutes are needed to carry the loaded buckets from the cut to an overhead plat- 

 form and load them on to a motor-truck 



the motor-trailers are backed. The 

 buckets used are mounted on wheels. 

 They are loaded in the cut and then 

 moved on tracks to the foot of the shaft 

 where they are picked up by the electric 

 crane and hoisted one at a time and 

 deposited on tracks on top of the double- 

 decked platform. By the time six of the 

 loaded buckets are thus placed, the 

 tractor unit has returned from the dump 

 with its load of six cmiit\' buckets, which 

 arc carried on tracks on the trailer. After 

 the trailer has been backed up to the 

 bumper, the adjustable drawbridge is 

 tilted from the top of the bumiwr to 

 the level of the lower platform, and the 



A Workshop on Every Farm 

 ACCORDING to one of the heads of 

 S\ a western agricultural college a. 

 source of economy that has been neglec- 

 ted in the past is the upkeep of farm 

 tools and implements. To overcome 

 this depreciation a workshop should be 

 erected. It need not be large, but 

 sufficiently roomy to allow for a work- 

 bench, a stove, and a certain amount of 

 floor space where the machinerA' or tools 

 ma>' be repaired or taken apart and re- 

 assembled. This will provide a proper 

 housing for all tools and implements 

 as well as a storage for defective and 

 broken parts. 



