العربية  الخليج  لدول التعاون  مجلس  لدول التقييس  ھيئة   
GCC STANDARDIZATION ORGANIZATION (GSO) 
 
  
 
 
مشروع:  نھائي   
 
 
 
 
GSO2/FDS/ECE 58: 2009 
  
  
  
 
 
  
 
  
 
  
إعداد 
 لقطاع الخليجية  الفرعية  الفنية اللجنة   والإطارات  المركبات  مواصفات  
 
   
  
قياس لمواص  مش  الوثيق  ھذه  فإنھ ل بش  والملحوظ  ال لإب توزيعھ  ت خليجي  ية
 مجل  م اعتمادھ  بع إلا خليجي  قياس  كمواص  إليھ الرج  يج ولا والتب  للتغيير  عرضة
الھيئة إدارة .  السيارات  - اختبارھا  وطرق  والمقطورات  للشاحنات  الخلفية  الحماية  حواجز   
MOTOR VEHICLES 
REAR UNDERRUN PROTECTI VE DEVICES FOR TRUCK 
AND TRAILER AND ITS METHODS OF TEST  
تقديم  
عضويتھا  في تضم إقليمية  ھيئة العربية  الخليج  لدول التعاون  مجلس  لدول التقييس  ھيئة   الأجھزة
 القياسية  المواصفات  إعداد الھيئة مھام ومن ، العربية  الخليج  دول في والمقاييس  للمواصفات  الوطنية
 متخصصة  فنية لجان بواسطة  الخليجية  . 
  
 الفني اللجن  عم برن  ض  العربي  الخل  ل التع  مجل  ل التقي  ھيئ قام وق
رقم2-1  "الخليج  الفنية اللجنة  والإط  المركب  مواص  لقط  الفرعية  ية "   المواص  بإع
 رق الخليجي  القياسGSO2/DS/ECE 58: 2009  "  الس   - الخلفي  الحماي  ح
اختبارھ  وط  والمقط  للش"    قب م  عم  س  بع المش  إع  ت وق
العربي القياسية  المواصفات  الصلةاستعراض  ذات المرجعية  والمؤلفات  والدولية  والأجنبية  ة  . 
    
 المواصفة  ھذه اعتمدت  قياسيةوقد  كمواصفة   خليجية         رقم الھيئة إدارة مجلس  اجتماع  في)           
      ( بتاريخ  عقد الذي ،         /      /       الموافق   ، ھـ/      /       م  . 
  
Foreword 
 
 
 
Standardization Organization for G CC (GSO) is a regional Organization 
which consists of the National Standard s Bodies of GCC member States. One 
of GSO main functions is to issue Gulf Standards /Technical regulation 
through specialized technical committees (TCs). 
 
GSO through the technical program of committee TC No  .2-1 "  The Gulf 
technical Subcommittee for vehicles and tyres standards " has prepared this 
Standard .  The Draft Standard has b een prepared by sultanate of Oman.  
 
 The draft Standard has been prepared  based on relevant ADMO, International 
and National foreign Sta ndards and references. 
 
This standard has be en approved as Gulf  Standard by GSO Board of Directors 
in its meeting No..../....  …….held on    /    /   /  H ,  /    /   G 
 
 2 
  MOTOR VEHICLES 
REAR UNDERRUN PROTEC TION IN TRUCK AND 
TRAILER AND ITS METHODS OF TEST 
 
 
 
1- SCOPE AND FIELD OF APPLICATION 
This standard is concerned with th e requirements for the rear underrun 
protective devices (RUPD) of trucks and trailers having maximum mass 
exceeding 3.5 tones used for the carriage of goods. This standard does not apply to Traction units for articulated ve hicles, special trailers constructed for 
the carriage of very long loads su ch as timber, steel bars etc. 
 
2- COMPLEMENTARY REFERENCES 
 
2.1 GSO 159/.1993.... “Motor Vehicles - Weights and Dimensions”. 
 2.2 GSO 48/.1984.... “Motor Vehicles - Conformity Certificates”. 
 
3- DEFINITIONS  
3.1 Unladen mass:   The mass of the vehicle in running order, unoccupied, and 
unladen but complete with fuel, coolan t, lubricant, tools and spare wheel. 
 3.2 Maximum mass:  The mass stated by the vehicle manufacturer to be 
technically permissible. 
 3.3 Rear underrun protective device (RUPD):   It consists of a cross-member and 
links to the chassis side members or ot her structural members of the vehicle. 
 3.4 Type of RUPD : RUPD which do not differ with respect to the essential 
characteristics such as shape, dime nsions, attachment, materials and the 
marking. 
   3 
  3.5 Rear Underrun Protection (RUP)  : The presence at the rear of the vehicle of  
either: a special RUPD or a body work, ch assis parts or other components such 
that by virtue of their shape and characteristics, these elements can be regarded as totally or partially fulfill ing the function of the RUPD.  
 
4- REQUIREMENTS 
 The following shall be met:  
 4.1 General 4.1.1 All vehicles carrying goods, including tankers, mobile cranes, mobile 
workshops, trailers and semi-trailers shall be equipped with rear underrun protective devices to protect against unde rrunning of vehicles in the event of 
rear collision with passenger cars, multi- purpose vehicles and light duty trucks 
having a maximum mass not exceeding 3.5 tonnes. 
4.1.2 The rear underrun protective device shall comply with the requirements 
specified in item 4.2. 
4.1.3 If the vehicle is so designed and equippe d at the rear that by virtue of their 
shape and characteristics, its component  parts comply with the requirements 
specified in items 4.2 and 4.3, then the vehicle may not be necessary to be provided with rear under run protective device. 
4.1.4 The maximum mass of a vehicle type for which the rear underrun protective 
device to be installed shall not exceed the value indicated on the rear underrun 
protective device for which it is designed for. 
 4.2 RUPD Technical requirement  
4.2.1 The section height of the RUPD me mber shall not be less than 100 mm. 
4.2.2 The lateral extremities of the cross-memb er shall not bend to the rear or shall 
not have a sharp outer edge . This requirement can be considered as complied if 
the lateral extremities of the cross member are rounded on the outside and have a radius of curvature of not less than 2.5mm. 
4.2.3 In case, if the rear underrun protectiv e device is designed to have several 
positions at the rear of the vehicle, there must be a guaranteed method of 
securing it in the service position, and the force applied by the operator to vary 
the position of the device shall not exceed 40 daN. 
4.2.4 The rear underrun protective device sha ll offer adequate resistance to forces 
applied parallel to the longitudinal axis of the vehicle. 4 
  4.2.5 When a horizontal force of 100 kN is applied to the rear underrun protective 
device, the distance between the rear of the rear unde rrun protective device and 
the rear extremity of the vehicle sha ll not exceed 400 mm at any of the points 
where the test forces are applied. 
4.2.6 For vehicles fitted with a platform lif t at the rear, the underrun device may be 
interrupted for the purposes of the mechanism. In this case, the following special requirements apply: 
 4.2.6.1 The maximum lateral clearance meas ured between the elements of the 
underrun device and the elements of the platform lift, which move through the 
interruption when the lift is operat ed and which make the interruption 
necessary, may amount to no more than 2.5 cm. 
 4.2.6.2  The individual elements of the underrun protection, incl uding those outboard 
of the lift mechanism, where provided, must  have an effective surface area, in 
each case, of at least 350 cm2. However, in the case of vehicles having a width 
of less than 2000 mm and where it is  impossible to achieve the above 
requirement, the effective surface may be reduced on the condition that the 
resistance criteria are met. 
 4.3 Installation of RUPD  indicate d in item 4.2  to the vehicle  
4.3.1 The ground clearance with respect to the underside of the protective device, 
even when the vehicle is unladen shall not exceed 550 mm over its entire 
width. 
4.3.2 The height above the ground of the point s of application of  the test forces 
applied to the device shall not exceed 600 mm. 
4.3.3 The width of the rear underrun protectiv e device shall not at any point exceed 
the width of the rear axle measured at the outermost points of the wheels. 
4.3.4 The width of the rear protective devi ce shall not be more than 100 mm shorter 
on either side than the width of the rear axle measured at the outermost points of the wheels. 
4.3.5 The device shall be so fitt ed that the horizontal distan ce between the rear of the 
device and the rear extremity of the vehicle, including any platform lift 
mechanism, shall not exceed 400 mm measur ed at any of the points where the 
test forces have been applied.  In m easuring this distance, any part of the 
vehicle which is more than 2 m above the ground when the vehicle is unladen 
shall be excluded. 
4.3.6   The maximum mass of vehicle type fo r which the RUPD is installed shall not 
exceed the value indicated on the RUPD  or with the approved document. 5 
   
4.4 Requirements for Rear Underrun protection (RUP)  
 4.4.1 The ground clearance with respect to th e underside of the RUP, even when the 
vehicle is unladen, shall not exceed 550 mm over its entire width. 
4.4.2 The RUP shall be situated as close to  the rear of the vehicle as possible. 
4.4.3 The width of the RUP shall not at no poi nt exceed the width of the rear axle 
measured at the outermost points of the wheels. 
4.4.4 The width of the rear protective devi ce shall not be more than 100 mm shorter 
on either side than the width of the rear axle measured at the outermost points of the wheels. 
4.4.5 Where the device is contained in or  comprised by the vehicle bodywork which 
itself extends beyond the width of the rear  axle the requireme nt that the width 
of the RUP must not exceed that of the rear axle shall not apply. 
4.4.6  The section height of the RU P shall not be less than 100 mm. 
4.4.7 The lateral extremities of the RUP shall not bend to the rear or have a sharp 
outer edge. This requirement can be c onsidered as complied when the lateral 
extremities of the RUP are rounded on th e outside and have a radius of 
curvature of not less than 2.5 mm. 
4.4.8 In case, if the rear un derrun protection device (R UP) is designed to have 
several positions at the rear of the vehi cle, there must be a guaranteed method 
of securing it in the service position, and the force applied by the operator to vary the position of the RUP shall not exceed 40 daN. 
4.4.9 The RUP shall offer adequate resistan ce to forces applied parallel to the 
longitudinal axis of the vehicle and be connected, when in the service position, 
with the chassis side-members or whatever replaces them. 
4.4.9.1 This requirement will be considered satis fied if it is shown that both during and 
after the application of the horizontal  forces described in item 6.3, the 
horizontal distance between the rear of the RUP and the rear extremity of the 
vehicle, including any plat form lift mechanism, does not exceed 400 mm at any 
of the points where the te st forces are applied. 
4.4.9.2 In measuring this distance, any part of the vehicle which is more than 2 m 
above the ground when the vehicle is unladen shall be excluded. 
4.4.10 For vehicles fitted with a platform lif t at the rear, the underrun device may be 
interrupted for the purposes of the mechanism. In this case, the following special requirements  shall apply: 6 
  4.4.10.1 The maximum lateral clearance meas ured between the elements of the 
underrun device and the elements of the platform lift, which move through the 
interruption when the lift is operat ed and which make the interruption 
necessary, may amount to no more than 2.5 cm. 
4.4.10.2 The individual elements of the unde rrun protection, includ ing those outboard 
of the lift mechanism, where provided, sh all have an effective surface area, in 
each case, of at least 350 cm2. 
4.4.10.3    In the case of vehicl es having a width of less th an 2 000 mm and where it is 
impossible to achieve the above requirem ent, the effective surface area may be 
reduced on the condition that th e resistance criteria are met. 
 
5- MARKING 
 
5.1 Each rear underrun protective device sh all be legibly and durably marked or 
labelled with the following information in Arabic and/or English. 
5.1.1 Manufacturers name and/or trademark. 5.1.2 Date of manufacture. 5.1.3 The maximum mass of vehicle on whic h the rear underrun protective device 
may be installed. 
5.1.4 A detailed description with sketches th e correct installation and adjustment of 
the device. 
5.1.5 Drawings, diagrams and layout plans of the components of the structure. 
 
6- TESTING 
 
6.1 Sampling 
 A sufficient number of r ear underrun protectiv e device shall be taken from the 
consignment of the devices of the same type and subjected to the required tests 
prescribed in this standard. 
 6.2 Measuring instruments 6.2.1 Dimension measuring instrument  The instruments used shall permit measurement to an accuracy of ( ± 1) mm. 
6.2.2 Force measuring instruments  The instruments used shall perm it measurement to an accuracy of ± 5% of the 
range. 
 7 
  6.3 Tests 
 The following tests shall be carried out  on the sample withdrawn in accordance 
with item 6.1. 
6.3.1 Visual inspection test  The rear underrun protective device shall be visually examined to check for 
any damage, crack, sharp outer ed ge or any apparent defects. 
6.3.2 Test conditions for RUPD    The test may be carried out either: 6.3.2.1 - On a vehicle of the type for which RUPD is intended 6.3.2.2 - On a part of the chassis of the vehi cle type for which the RUPD is intended, 
this part shall be representative  of the vehicle type in question 
6.3.2.3      - On a rigid test bench 6.3.3 Test conditions for vehicles. 
- The sample shall be installed on to a vehicle of the type for which the rear 
underrun protective device is intended or  part of the chassis or on a rigid 
bench. 
- The vehicle shall be at rest on a level, flat, rigid and smooth surface. 
- The front steered wheels shall be  in the straight-ahead position. 
- The vehicle shall be unladen. - The tyres shall be inflated to the pressure recommended by the vehicle 
manufacturer. 
- The vehicle shall be restrained by a suitable method as specified by the 
manufacturer to or restrained  by any method specified by the 
manufacturer. 
- If the rear underrun protective device is  installed to a trailer, the trailer 
shall be coupled to the tractor. 
- Vehicles equipped with hydropneumatic, hydraulic or pneumatic 
suspension or a device for automatic leveling according to load shall be 
tested in the normal running conditio n specified by the manufacturer. 
6.3.4 Procedure  The measurements shall be made on the rear underrun protective device 
installed in accordance with item 6. 3.2 and the compliance with items 4.2, 4.3 
and 4.4 shall be checked. 
 6.3.5 Strength test 6.3.5.1 Apparatus 8 
   The apparatus shall consists of a suit able mandrel of maxi mum height 250 mm, 
200 mm wide, with a radius of curvature of (5 ± 1) mm at the vertical edges. 
6.3.5.2 Preparation for the test  The vehicle shall be prepared for the tests as explained in item 6.3.3. 
6.3.5.3 Procedure 6.3.5.3.1 The test vehicle shall be positione d on a horizontal flat surface. 
6.3.5.3.2 The height of the mandrel shall be ad justed so that the height above the 
ground of the centre of the impact  surface shall not exceed 600 mm. 
6.3.5.3.3 A horizontal force of 100 kN or 50% of the force generated by the 
maximum mass of the vehicle, whichever is the lesser, shall be applied consecutively to two points situated sy mmetrically about the centre line of 
the device or of the vehicle whichever is applicable at a distance of (700 to 1000) mm. 
6.3.5.3.4 In the cases defined in items 6.3.2.1 and 6.3.2.2 a horizontal force of 50 kN 
or 25% of the force generated by the maximum mass of the vehicle, 
whichever is the lesser, shall be applied consecutively to two points located (300 ± 25) mm from the longitudinal planes  tangential to th e outer edges of 
the wheels on the rear axle and to a third point located on the line joining 
these two points, in the median vertical plane of the vehicle. 
6.3.5.3.5 In the cases defined in item 6.3.2.1 a horizontal force of 50 kN or 25 per 
cent of the force generated by the ma ximum mass of the vehicle for which 
the device is intended, whichever is the lesser, shall be applied consecutively to two points located by the manufacturer of the rear 
underrun protective device and to a thir d point located on the line joining 
these two points, in the median vertical plane of the device. 
 6.3.5.4 Replacement force application points:  If any point defined under item 6.3.5.1, is  located within th e interruption area 
of the underrun protection device as mentioned in paragraphs item 4.2.6 or 4.4.10 of this Regulation, the test for ces shall be applied at replacement 
points located: 
6.3.5.4.1 for the requirement under item 6.3.5.3.3, on the horizontal centerline and 
within 50 mm of each vertical edge closest to the intended points of force application, as defined in that paragraph, and 
6.3.5.4.1 for the requirement under paragraph item 6.3.5.3.4, at the in tersection of the 
horizontal and vertical cente rlines of each element furt hest from the vertical 
centerline of the device or  of the vehicle, whicheve r is applicable.  These 9 
  points should be a maximum of 325 mm from the longitudinal planes 
tangential to the outer edges of  the wheels on the rear axle. 
6.3.5.5 Result  At the end of each test the distance between the rear of the rear underrun 
protective device and the rear extremity of  the vehicle at any of the points shall 
be measured. 
 
 
7- CRITERIA OF TECHNICAL CONFORMITY  
7.1 The criteria of technical conformity  shall be in accordance with the Gulf 
Standard G.S. 48/1984 “Motor Vehicl es - Conformity Certificates”. 
7.2 The rear underrun protectiv e device shall be considered  complying with all the 
requirements of this standard when the withdrawn sample from the consignment or the supplied sample by the manufacturer passes the tests. 
 7.3 In case one or more rear underrun protect ive device in the samp le fails to pass 
the tests, a second sample double the numbe r of units as the first one shall be 
withdrawn from the same consignment or  the supplied sample and subjected to 
the tests. 
 The rear underrun protective device sh all be considered complying with the 
requirements of this standard when all the units of the second sample pass the 
tests, otherwise the rear  underrun protective device shall be considered non-
complying.