Transport of materials during construction of =he Nurek dam is effec=ed mainly by motor dump trucks BelAZ-540 and KrAZ-222. At the present time a trial/production conveyor line has been constructed, 4.6 km long and with a belt width of 1200 mm, along which it is proposed to transport nearly 3million m s of gravel from borrow area No. 12 to the dam. The rest of =his material will be hauled mainly by dump trucks BelAZ-540. The operating conditions for these trucks are becoming more complex as =he dam height and the depth of the borrow areas increase. This creates certain characteristics and limitations in the =ravel regimes of motor dump trucks and operation of their power units.In order to optimize the work of assemblies and units along the most heavily loaded ring road from gravel borrow-area No. 9 to the dam, and their working conditions on steep grades, full-scale investigations were carried our on the dump trucks, using special measurinE-recording equipment. An oscillograph K-12-22 was installed, on which the following parameters were registered: Rate of rotation of the diesel shaft, nd; rotational speed of dump truck's front wheel, nw; rate of rotation of secondary shaft of the hydromechanical transmission (HMT), nwg ; No. of the engaged gear of the HMT, Zwg; application of the wheel brakes, hr, h~; application of hydraulic-brake/decelerator, hh; temperature of cooling fluid in engine, =f; temperature of oil at exit point from =he HMT, =~.Experimental =rips were made, hauling gravel from the borrow area along two routes: Along the ring road, with one-way traffic, and along =he left ba~k, with ~wo-way traffic (see Fig. i). Along the firs= route =he loaded BelAZ trucks cross from the left =o the right bank along a bridge specially constructed for the ring road. For 3 km the road has an average grade of 2.6%, and over the last 300 m before =he dam the grade is 9-10%. The 2.7-km leftbank road has an average grade of 5.6%, of which i000 m is graded 8-I1%. Ten cycles of observations were made with a continuous recording of the above-mentioned parameters. The data on travel regimes thus obtained were processed according =o calibration data, applying mathematical statistical methods. The total travel time along =he firs= route was 11% longer than along =he second, =he number of gear changes was 35% greater, but =he proportion of time that the HMT operated in first gear was 16% less than when working along the second route; the maximum temperatures of oil and water were also somewhat less. The analytical data showed that with one-way traffic =he rime per cycle (trip) was practically the same as for two-way traffic. However, taking into account =hat the investigations were conducted in September-October and that during this period =he monthly output of fill totaled 450,000-500,000 m s (maximum, 1 million m3), preference had =o be given =o =he ring route, which has greater possibilities for intensifying materials transport =o the dam.Construction progress of the dam predetermines utilization of travel patterns for mo=D...