Pakistan Standard Specifications for Truck Chassis (Part-1)


    The increasing transport requirements both for passengers and goods give rise to serious questions of road safety and environmental security which are since a challenge for traffic policy makers, transport corporations including private fleet operators and, above all, for the vehicle manufacturers. Consequently, it is also obligatory for the Body Fabricators to change and adapt to the much needed change without compromising on basic minimum requirements of safety comfort and safe load handling and carrying. The Technical Committee of EDB/PAMA has addressed the current problem of absence of standards for local fabricators of bodies on Rigid Trucks Chassis and the exercise undertaken by the said committee was aimed towards standardizing the essential aspects involved in the fabrication of bodies on rigid trucks chassis considering the minimum requirements of safety and comfort for the passengers and the driver and for safe handling and damage free transport of cargo.

    In the existing situation, the underlying principle was identified to distinguish that the vehicle manufacturers (OEMs) sell their products in the form of drive away chassis and the majority of design Body Fabrication is done by way side unorganized sector and this is the normal practice throughout the country. To bring and give consistency to design and Body Fabrication to improve their standards to bring safety to the body and the vehicle, the necessity of the standards was desired for uniform applicability throughout the Country.

    This exercise of formulation of the requisite guidelines had been done for the first time in the country by a PAMA Technical Committee under the authority of Engineering Development Board and PSQCA. The Committee has looked into various aspects and has carried out detailed deliberations of the relevant issues. With the procedure in place, it is all the more essential to introduce a “Scheme of Accreditation” of Body Fabricators, including Body Manufacturers and Vehicle Modifiers, so that the implementation could be fair and uniform in the country.

    CHAPTER – 1


    The requirements specified hereunder shall constitute a standard for fabrication of bodies on Rigid Trucks Chassis manufactured by Commercial Body Manufacturers (CBM) and meant for the transportation of general cargo capable of operating at speed within range of 30-55 km/hr within City Areas and speed range of 40-90 km/hr on Highways/Motorways.

    1.1          These standards do not cover Special Purpose Transport Tractors, Trailers, Special purpose Vehicle for the Transportation of Goods of Excessive Load and Dimensions and Agricultural Tractors.

    1.2          These standards provide the basic guide lines to the commercial body manufacturers which they have to incorporate in their design and the same should be in conformity with specifications of Original Equipments Manufacturers and automotive engineering standards with respect to the function, materials, manufacturing quality, workmanship, dimensional limits and basic safety characteristics of the final product made out of a truck chassis.

    1.3          This document directs design characteristics required for fabrication of bodies besides providing valuable information and guidance to those concerned with the preparation of specifications and the procurement of commercial vehicles.

    1.4          These standards are to be used in the design, fabrication of trucks bodies including modification / retrofitting of the existing or new vehicle procured from an OEM as simple rigid trucks chassis with cabin only.

    CHAPTER – 2


    2.1 Heavy Commercial Vehicles (HCV):

    Vehicle having a gross vehicle weight (GVW) rating of more than 5 tons, which have either separate closed rear area or an open rear platform normally used for the transport of goods or passengers and shall include the following, namely;

    These HCV’s are further grouped on the basis of GVW, which are as follows

    5 ~ 8 Tons GVW

    8 ~ 20 Tons GVW

    20 Tons & onwards

    These groups are normally termed as Light, Medium and Heavy Commercial Vehicles.

    2.2          Superstructure:

    Any structure added or built on the truck’s chassis. It can be container / extensions / canopy / attachments for storing goods or carrying passengers.

    2.3          Undercarriage:

    All the components mounted under the frame in heavy commercial vehicle. This includes axles, shock absorbers, wiring harness, brake tubes, rims, spare wheel carrier, leaf springs, fuel tank and Tubing’s, air cleaner, muffler, exhaust pipe, battery along with its carrier etc.

    2.4          Payload: Actual weight of cargo carried by a vehicle.

    2.5          GVW: (Gross Vehicle Weight)

    It is the Total weight carried by a Truck including its own weight.

    G.V.W= (Curb Weight + Body Weight + Payload + Crew Weight)

    2.6          Curb weight: It is Combination of Truck Chassis and cabin weight alone. (Weight of unloaded vehicle).

    2.7          Power to Weight ratio: Power-to-weight ratio measure commonly used when comparing with various vehicles.

    It is the Ratio of power generated by an Engine (Rated in Horse Power, divided by the Gross Vehicle Weight measured in Tons).

    2.8          Grade ability: It means the percentage of grade that a truck of certain specification can climb with a specific Gross Weight.

    2.9          Tractate Force: It is the force exerted by the tires on the road, is torque transmitted through the clutch, transmission, propeller shaft, wheels. This force makes vehicle to move in certain direction called tractate force.

    2.10        Overall Height/Length/Width:

    These dimensions should be in accordance with the Motor Vehicle Regulations.

    2.11        Wheel Base: It is the linear distance between the axis of tires mounted on front and rear axle (Varies from make to make). However in 6X2 configuration, it is either of the following, the linear distance between the wheels mounted on front axle and the mean distance of two wheels mounted on rear axles.

    2.12        Original Equipment Manufacturers (Auto): Manufacturers/Assemblers of Heavy commercial Vehicle (HCV) and approved by the Engineering Development Board (EDB), Government of Pakistan, in the automobile category.

    2.13        Commercial Body Manufacturers: (CBM): Stand for designers, fabricators and manufacturers engaged in different activities as mentioned below, licensed by Regional Transport Authority of the respective Provincial Government for Body Fabrication/Building to issue a Body Building Certificate for registration with the excise authorities in the respective category:-

    1.            Body Builders, engaged in the designing and fabrication of different types of commercial cargo bodies on rigid truck chassis.

    2.            Vehicle Builders, engaged only in the installation of the pre fabricated commercial bodies on rigid truck chassis.

    3.            Vehicle Re Builders and Modifiers, engaged in the rebuilding of the old vehicles bodies, or engaged in the modification activities to upgrade, change the configuration and specifications of the vehicle.

    2.14        Un-Authorized Modification: Any changes in the basic configuration of the chassis which are not in line with the OEM’s (Auto) recommendations and or violating the prevailing motor vehicle laws.

    2.15        Conversion: Making a change in the basic OEM’s configuration of the chassis, which includes change of engine, transmission and the like, shall be classified as conversion.

    2.16        Alteration: Any activity which leads to changes in the OEM’s specifications of a vehicle, partially or wholly such as altering into an entirely different type of vehicle from its original specifications such as altering the wheel base, over hangs etc.

    2.17        Retrofitting: Retrofitting refers to the addition and or substitution of new technology or features to the older system, like installation of power steering, power windows, power mirrors, cruise control, remote key less system, electronic fuel pumps etc.

    2.18        Authorized Modification: Carrying out minor alterations on the chassis, like moving of parts from original locations to another place to accommodate fabrication of commercial bodies. For example relocating of battery, fuel tank, spare wheel etc.

    2.19        Modified Vehicle: Vehicles whose basic configuration and or specifications have been changed either by conversion or by alteration.

    2.20        Common Upgrades: Common upgrades includes the replacement of the OEM supplied parts with the aftermarket parts for further improvement in the vehicle specification and performance, this include replacement of tires, disc wheels, radiators, exhaust system, fuel tanks etc.

    2.21        Major Modifications:

    a. Any modification which leads to change in the classification and or categorization of a truck chassis.

    b. Conversion from truck to bus chassis or vice versa.

    c. Conversion of rigid trucks to prime movers and vice versa.

    d. Conversion from 4×2 to 6×2 or 6×4 and vice versa.

    e. Conversion of structures or bodies from one type to another as defined above.

    2.22        Certificate of Modification: The certificate issued by government licensed body builders/vehicle builder/vehicle rebuilders and modifiers for the purpose of registration of the modified vehicle with the excise authorities as stipulated at clause 2.13 above.

    2.23        Drive Away Chassis: Means the basic vehicle with or without cabin but includes engine, frame, exhaust, cooling, braking and systems in addition to necessary electrical, mechanical and structural parts.

    2.24        Weight Distribution on truck: It means the distribution of the body and the payload and the relationship with respect to the acceptable load on the axles.

    2.25        Long Member or Chassis Frame: They are structural members that support the cross members and help to transmit the load from cross members to the chassis.

    2.26        U-Bolts: The fasteners used for fastening the cross members or sub frame to the chassis frame.

    2.27        Outrigger: Members are provided to transfer load or body structure members; they are fixed to the chassis side members.

    2.28        Head Board: Stand for the structural members that are provided for supporting the load and act as load bearing members.

    2.29        Platform: Stand for structural members that are provided for supporting the load and act as load bearing members and are capable of withstanding vertical forces acting on it during the transportation.

    2.30        Side Gates / Board: Stand for structural members that are provided for supporting the load and act as load bearing members and are capable of withstanding horizontal forces (Side thrust) induced on it during the transportation.

    To be continued…

    Published on pages#22 & 23, April-2016 edition of MOBILE WORLD Magazine