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Axle Spray Suppression, Wings and Wheel Arches

Regulation 64 Road Vehicles (Construction and Use) Regulations 1986 states that suitable spray suppression equipment (to British Standard or EC 91/226) should be fitted on each axle. There are exceptions to these requirements with a full breakdown of which vehicles spray suppression is applied to below; 

Please find below information relating to; 

  • Vehicle Types affected 
  • Vehicle Types exempt

Spray Device Maintenance  

Regulation 65 Road Vehicles (Construction and Use) Regulations 1986 states that every part of every spray suppression device is required to be fitted and Regulation 64 states it shall at all times when the vehicle is on the road be maintained free from any obvious defect which would be likely to affect adversely the effectiveness of the device. 

Vehicle Types Affected 

Spray suppression and containment equipment must be fitted to many vehicles. Apart from certain exemptions, the vehicles affected are as follows:

  • Motor vehicles over 12 tonnes maximum gross weight, first used on or after 1 April 1986 
  • Trailers over 3.5 tonnes maximum gross weight, manufactured on or after 1 May 1985 
  • Trailers over 16 tonnes maximum gross weight with two or more axles 

(EC Regulation Vehicles over 7.5 tonnes and Trailers exceeding 3.75 tonne GVW after 10 April 1992) 

Equipment must be fitted in relation to the wheels on each axle and must meet the British Standard specification for spray reducing devices for heavy goods vehicles (BS AU200). Alternatively, vehicles may be fitted with spray suppression devices of a  type approved to the EU standard in Directive 91/226. This performance standard is marginally higher than the British Standard. BS AU200 stresses three aspects of design as follows:

  • Containment around the wheels in the form of wheel guards, valances and wheel flaps
  • Filling suppression devices
  • Paying due regard to vehicle aerodynamics 

Three categories of suppression and containment systems are covered by the standard which are:

  • a conventional type of wheel guard with a valance and wheel flap
  • longitudinal strips and a flap of suppressant material
  • an air/water separator 

The equipment must at all times, when the vehicle is on a road, be maintained free from any obvious defect likely to limit its effectiveness. 

The Department for Transport has obtained a legal opinion that wheel flaps must be, at least, as wide as the tyre(s) and not just the tyre tread. 

Regulation 64 - Spray suppression devices

(1) Save as provided in paragraph (2), this regulation applies to every wheeled goods vehicle which is: - 

  1. A motor vehicle first used on or after 1st April 1986 having a maximum gross weight exceeding 12,000 kg
  2. A trailer manufactured on or after 1st May 1985 having a maximum gross weight exceeding 3500 kg or 
  3. A trailer, whenever manufactured, having a maximum gross weight exceeding 16,000 kg and 2 or more axles. 

(2) This regulation does not apply to:

  1. A motor vehicle so constructed that the driving power of its engine is, or can by use of its controls be, transmitted to all the wheels on at least one front axle and on at least one rear axle
  2. A motor vehicle of which no part which lies within the specified area is less than 400 mm vertically above the ground when the vehicle is standing on reasonably flat ground
  3. A works truck
  4. A works trailer
  5. A broken-down vehicle
  6. A motor vehicle which has a maximum speed not exceeding 30 mph
  7. A vehicle of a kind specified in sub-paragraphs (b), (c), (d), (e), (f), (g), (h), (j), (k), (o) or (p) of regulation 51(2)
  8. A vehicle specially designed, and not merely adapted, for the carriage and mixing of liquid concrete or 
  9. A vehicle which is being driven or towed to a place whereby previous arrangement a device is to be fitted so that it complies with the requirements specified in paragraph (3). 

(3) A vehicle to which this regulation applies and which is of a class specified in an item in column 2 of the Table shall not be:

used on a road on or after the date specified in column 3 in that item, unless it is fitted in relation to the wheels on each of its axles, with such containment devices as satisfy the technical requirements and other provisions about containment devices specified in the British Standard Specification, provided that in the case of a containment device fitted before 1st January 1985 the said requirements shall be deemed to be complied with if that containment device substantially conforms to those requirements. 

Table (Regulation 64(3) 

Item 

Class of Vehicle 

Date 

1 

A trailer manufactured before 1st January 1975 

1 October 1987 

2 

A trailer manufactured on or after 1st January 1975 but before 1st May 1985 

1 October 1986 

3 

A trailer manufactured on or after 1st May 1985 

1 May 1985 

4 

A motor vehicle 

1 April 1986 


(4) In this regulation:

The British Standard Specification means the British Standard Specification for Spray Reducing Devices for Heavy Goods Vehicles published under the reference BS AU 200: Part I: 1984 and BS AU 200: Part 2: 1984 and references to a “containment device” are references to the device so described in the British Standard Specification; 

“the specified area” means the area formed by the overall length of the vehicle and the middle 80% of the shortest distance between the inner edges of any two wheels on opposite sides of the vehicle (such distance being ascertained when the vehicle is fitted with suitable tyres inflated to a pressure recommended by the manufacturer, but excluding any bulging of the tyres near the ground) 

(5) Nothing in this regulation derogates from any requirement specified in regulation 63. 

Regulation 65 - Maintenance of Spray Suppression Devices

Every part of every containment device with which a vehicle is required to be fitted by the provisions of Regulation 64 shall at all times when the vehicle is on a road be maintained free from any obvious defect which would be likely to affect adversely the effectiveness of the device. 

The following links provide guidance and further information

Construction & Use Regulations 1986 – Spray Suppression 
https://www.legislation.gov.uk/uksi/1986/1078/regulation/64/made 

Hgv Inspection Manual (pdf, 6.8 MB)

Heavy Goods Vehicle Inspection Manual, Section 14 (Spray Suppression, Wings and Wheel Arches)

Psv Inspection Manual (pdf, 13.1 MB)

Public Service Vehicle Inspection Manual, Section 14 Wings and Wheel Arches