UK Regulations for Wheelhouse and Trailer Sizes

In the UK, various regulations govern the dimensions, weight limits, and specifications for vehicles, including wheelhouses and trailers. Below is a comprehensive guide to UK regulations regarding trailer sizes, lengths, and allowable weights, including wheelhouses and specifications for trailers such as 20ft, 24ft, 30ft, and 40ft trailers.

  1. General Trailer Regulations in the UK

Legal Trailer Dimensions

The UK follows specific regulations on the length, width, and height of trailers. These dimensions apply to both commercial and private vehicles transporting goods.

  • Maximum Width:
    • The maximum allowable width for a trailer is 2.55 meters (255 cm). This includes the body of the trailer and any attachments such as mudguards or lights.
  • Maximum Length:
    • The maximum allowable length for a trailer varies based on its configuration:
      • Single-axle trailers: Maximum of 7 meters (7,000 mm).
      • Multi-axle trailers: For articulated lorries, the trailer length can be up to 12 meters (12,000 mm). For trailers such as those with 20ft, 24ft, 30ft, and 40ft lengths, these fall under the category of multi-axle articulated trailers.
  • Maximum Height:
    • The standard height limit for trailers is 4.65 meters from the ground to the highest point of the vehicle. However, specific types of trailers may have additional restrictions based on the cargo or equipment being transported.
  • Maximum Weight:
    • Gross Vehicle Weight (GVW): This includes the weight of the trailer plus its load.
      • For standard trailers, the maximum allowable weight is 3,500 kg.
      • For articulated lorries and larger trailers, the weight limit is typically 44,000 kg (44 tons), but this can vary depending on axle configurations and road conditions.
  1. Types of Trailers and Their Specifications

20ft Trailer

  • Length: 6.1 meters (20 feet).
  • Width: 2.55 meters (standard width).
  • Height: Maximum of 4.65 meters.
  • Maximum Weight: Up to 3,500 kg (single axle) or more with multiple axles (up to 44,000 kg depending on configuration).
  • Axles: Usually, 2-axle design.
  • Common Uses: Suitable for standard freight or container transport.

24ft Trailer

  • Length: 7.32 meters (24 feet).
  • Width: 2.55 meters.
  • Height: Maximum of 4.65 meters.
  • Maximum Weight: Similar to the 20ft trailer, it ranges from 3,500 kg for single axle to 44,000 kg for multi-axle trailers.
  • Axles: Generally, 2 to 3 axles.
  • Common Uses: Used for slightly larger cargo than 20ft trailers, especially in distribution and larger freight.

30ft Trailer

  • Length: 9.14 meters (30 feet).
  • Width: 2.55 meters.
  • Height: Maximum of 4.65 meters.
  • Maximum Weight: Again, the maximum weight is dependent on the axle configuration but can go up to 44,000 kg.
  • Axles: Typically 3 axles for increased load capacity.
  • Common Uses: Often used for bulk transport of goods and larger containers.

40ft Trailer

  • Length: 12.19 meters (40 feet).
  • Width: 2.55 meters.
  • Height: Maximum of 4.65 meters.
  • Maximum Weight: Similar to the other trailers, can range up to 44,000 kg, dependent on axle configuration.
  • Axles: Typically 3 to 4 axles.
  • Common Uses: Common in international freight transport, especially in containerized shipping.
  1. Weight Limits for Different Trailer Types in the UK

The weight limit for trailers is generally governed by the axle configuration and whether the trailer is being used for commercial or non-commercial purposes.

  • Single-axle trailers (typically smaller trailers, under 3.5 meters in length) are limited to 750 kg (gross weight).
  • Tandem-axle trailers or multi-axle trailers can carry heavier loads, generally ranging between 3,500 kg and 44,000 kg, depending on the number of axles and vehicle classification.
  • Articulated lorries: Maximum permissible weight is 44,000 kg, but the exact limit can vary by the number of axles and any specific local permits or weight restrictions.

Note: Exceeding these weight limits may require a permit or a special license, especially for oversize or overweight loads.

  1. Trailers: General Specifications
  • Axles: Trailers can be designed with 2, 3, or more axles, depending on the weight and type of load. More axles allow for greater weight capacity but also require stricter safety standards and inspection requirements.
  • Suspension: Trailers may feature air suspension, mechanical suspension, or other types of suspension, depending on the needs of the load and the road conditions.
  • Braking System: Most trailers above a certain weight require a braking system. Larger trailers typically have air brakes, while smaller ones may use electric brakes.
  1. Regulations for Wheelhouses

A wheelhouse is typically a structure on a trailer or vehicle that houses the wheels and axle(s), sometimes extending into the body of the trailer to protect or enclose the wheels.

Key Regulations for Wheelhouses:

  • Maximum Height: The wheelhouse must not obstruct the maximum allowable height for the trailer, which is 4.65 meters from the ground to the highest point.
  • Wheelhouse Design: In many cases, wheelhouses are used to shield the wheels and protect them from damage during transit. They must be designed with adequate clearance for the wheels and should not cause excessive drag or wind resistance, which could affect fuel efficiency or the ability to pass through regulatory checks.
  • Width Considerations: The wheelhouse, when designed, should not cause the trailer to exceed the maximum width of 2.55 meters unless special permits are obtained for wide load transportation.
  • Safety and Structural Integrity: The wheelhouse must meet UK safety standards, which include proper fastening mechanisms, strength for carrying loads, and compliance with weight distribution regulations.
  1. Additional Considerations and Permits
  • Special Permits: Oversized or overweight vehicles, including trailers with larger wheelhouses, may need a Special Vehicle Permit from the relevant local authorities or the Highways Agency in the UK. These permits often come with route restrictions and time limitations.
  • Load Restrictions: Specific goods, such as hazardous materials, may have additional requirements for both trailer design (e.g., specific braking or containment systems) and operational protocols (e.g., escort vehicles).

Conclusion

The UK has strict regulations regarding trailer sizes, wheelhouses, and weight limits. For trailers, the general regulations are as follows:

  • Standard Lengths: Trailers can vary in length from 20ft to 40ft with corresponding width and height restrictions.
  • Weight Limits: Commercial trailers can carry loads up to 44,000 kg, depending on their axle configuration.
  • Wheelhouse Regulations: Wheelhouses must comply with height and width limits and may require permits if the dimensions exceed standard restrictions.