News & Media

BPW LL Self-Steering Axles compliant with new longer semi-trailer regulations.



The Department of Transport (DfT) announced that from 31 May 2023, new legislation changes were introduced to permit longer semi-trailer (LSTs) combinations, with a maximum length of 18.55 metres, on roads in Great Britain – 2.05 metres longer than the standard size. LSTs will support the government’s priority to further economic growth, emission reduction and strengthening supply chains.


The introduction of LSTs will facilitate the transportation of larger quantities of goods, resulting in a reduction of 8% fewer journeys than current trailers. This is expected to generate £1.4 billion in economic benefits and take one standard-size trailer off the road for every 12 trips, further contributing to enhanced logistics and environmental sustainability. Vehicles which use LSTs will be subject to the same 44-tonne gross combination weight limit as those using standard trailers. These new vehicles are also expected to cause less wear on the road than conventional trailers due to the type of steering axles used.


The move follows an 11-year trial, confirming the well-established benefits of increasing vehicle capacity: reduced costs, estimations of saving 70,000 tonnes of carbon dioxide from being released into the atmosphere and a reduced number of trailers on our roads. After an active involvement in supporting the trials, BPW welcomes the approval which demonstrates the improvement in transport efficiency that can be achieved with the right technology.


BPW LL SELF-STEERING AXLE: With its unique capabilities, the BPW LL self-steering Axle not only enables compliance with the new LST regulations but also delivers substantial environmental, and economic advantages providing an advanced and intuitive system that offers unparalleled benefits to the industry. The simple passive steering components enable automatic, load-dependent control.


The traditional benefits of BPW’s LL self-steer axle have been well documented: these include enhanced manoeuvrability, lower fuel consumption, lower tyre costs, and reduced stress on the chassis. The benefits are simply achieved: BPW’s self-steering axle operates without the need for power-assisted steering control stabilisers. It is automatically controlled according to the load being carried, and because the design itself is so simple, the number of individual components required is low. This saves weight and reduces installation and maintenance costs.


ENHANCED MANOEUVRABILITY AND STABILITY: Conventional active and control steering axle designs require steering stabilisers powered from an external source – this is not the case with the BPW self-steering axle. The axle beam and axle stub are connected to corrugated thrust bearings mounted under the kingpin assemblies. When driving straight (zero position), the corrugations in the thrust washers keep the wheels on track, while the vehicle’s weight is used to keep the washers in contact providing load-sensitive damping and ensuring optimal performance.


LL stands for ‘load-dependant steering stabilisation’ and it describes the unique functional principle of the BPW self-steering axle. BPW’s LL steering axle has been designed with a self-locking facility when reversing. Unlike other systems, as soon as the trailer begins to move backwards, the steering mechanism is locked in the straight-ahead position. Forces acting on the tyres when cornering are distributed more evenly. As a result, it has been shown that the life of the tyres on the front axle increases by up to 50%, while those on the rear axle can increase by as much as 70%.


The LL self-steering axle shows off its strengths particularly thanks to its greater manoeuvrability on corners and when making turns, you benefit from more straightforward vehicle handling, less tyre wear and lower fuel consumption – over a distance of 100,000 kilometres that adds up to as much as 1,000 litres of fuel saving and more than 4 tyres per vehicle - just work that out for your entire fleet!


COMPLIANCE AND CONVENIENCE: According to the DfT, operators will be legally required to ensure the implementation of appropriate route plans and risk assessments that account for the unique specifications of LSTs. Alongside these newly imposed legal requirements, operators will also be expected to conduct extra safety checks including driver training and scheduling, record keeping, training for transport managers, and proper loading practices of LSTs.


With the ever-increasing demands placed on fleet managers, it is essential to have a solution that optimises efficiency and prioritises safety and sustainability. BPW LL self-steering Axles provide a reliable and efficient solution, ensuring compliance with new laws governing longer semi-trailers. By incorporating these axles into their fleets, managers can optimise their operations and maximise load capacity while remaining fully compliant.


27 DEGREES OF STEER: The BPW LL self-steering axle is available with steering angles of between 12 and 27 degrees, with the latter being suited for longer semi-trailers. Based on the proven beneficial principles of their existing self-steer, this additional angle of steer enables allocated licence holders of 15.65-meter trailers to consider a self-steer axle, with no sacrifice of payload capability, against a more costly and heavier active or command steer system on their trailers.




24 May 2023


For further press information, contact Rebecca Wesley, Emma Makings-Hone or

Sandie Slavin at BPW Limited:

Telephone: 0116 281 6100 | Email: [email protected] |

[email protected] | [email protected]