Today reference books and technical documentation. devoted to techniques of selection park of special equipment for laying of pipelines, lost relevance owing to prompt development of an assortment number of this type of the equipment. That, in turn, resulted in need to establish criteria of equipment selection, describing dependence of efficiency of construction on technical and operational characteristics of the concrete pipelayer.

For a solution the two-level assessment of pipelayer efficiency is offered.

At the first level quality standard of overall performance of motor-transmission installation of the pipelayer by means of the criteria estimating completeness of realization of a mode of the maximum traction power, speed and fuel profitability is given. The first level is approved in works [1, 2], and in this article isn't provided.

At the second level the quantitative assessment of overall performance of MTU is given. Productivity is that criterion which coordinates all key technical parameters of the pipelayer and the parameters defining service conditions in the general mathematical dependence (model). Imposing on mathematical dependence boundary conditions, it is possible to create some private models describing process of laying of the pipeline.

Productivity (m/h) of the pipe layer is determined by a formula:

(1)

where Lс/к.– length of the raised site of the pipeline the extreme or average pipe layer, m; Tц – duration of a cycle of operation of the pipelayer, sec.

The duration of a work cycle Tц (sec.) is determined by a formula [3]:

(2)

where tпод.к, tоп.y, – the time of a raising and lowering of the pipeline, a lash or a pipe, sec.; tперем.i – the time spent for movement of the pipeline from a variable or constant loading, sec.; tкппj – the time spent for gear shiftings, sec.; tс.о.и. – the time spent for welding, clearing, insulating works, sec.; tx.x.z. – the time for an interval without loading (pipe layer idling), sec.

Figure 1 - The cyclogram of the pipelayers operation

, (3)

where ΔSi – an interval of a way cycle of the pipelayer with a variable or constant loading, m; Δh(под.к), Δh (oд.у) – an interval of a raising and lowering of the pipeline, m; ΔS(x.x.z) – an interval of idling of the pipelayer without loading, m; n(дв.i, k, y, z) – frequency of rotation of a cranked shaft of the engine on i, k, y, z an interval of a way, turn/min; r(зв. ) – radius conducting asterisks, m; r(бр.) – radius of a drum of the winch, m; U(mрj) – the general transfer relation of transmission on j to transfer; Uлб – the transfer relation of the winch; M(дв.i) – an engine torque on i-m an interval of a way, nm; M(дв.мах) – the maximum torque of the engine, nm; a – parameter is presented, as function not only φкр.мах which can change owing to dynamics of loading but also as function φкр.мах(constant for this soil limit coefficient of coupling at hundred percentage slipping); φкр – coefficient of coupling of the crawlers propeller; η(mр.j) – the general efficiency of transmission on j to transfer; f – coefficient of resistance to movement of crawlers; α – a bias of a surface of movement (a plus – when lifting, a minus – at descent); f1 – effort coefficient when lifting pipeline by the pipelayer; B – the coefficient gets out depending on geometrical and strength characteristics of a pipe.

The main the advantage of the given mathematical dependence (model) is the interrelation: forces of resistance, traction efforts, power ratios. The two-level assessment of efficiency gives the chance to carry out the predesign analysis of special equipment with known parameters in the set service conditions, but also to recommend the modern analogs which are meeting the requirements of the specification for use.

2 Shevchyuk V.P. The calculation of the special working equipment for MTU of industrial function.: monograph / Shevchyuk, M. V. Lyashenko, V.V. Shekhovtsov, A.V. Pobedin, K.O. Dolgov, N. V. Krivosheev. – Volgograd: Publishing house of educational and scientific literature VSTU, 2011. – 148 pages.

3. Shevchyuk V.P. The Mathematical Simulation Effectiveness Parameters of Machine-Tractor Unit during Pipelaying Works [electronic resource] / V.P. Shevchyuk, V.V. Shekhovtsov, N. V. Krivosheev // 32nd Seminar of the Studentds` Association for Mechanical Engineering, Warsaw, Poland, 15-17.05.2013 : [papers] / Military University of Technology, Faculty of Mechanical Engineering. – 1 CD-ROM. – Warsaw, 2013. – S. 1–5.