LST Trailers | 15.65m Longer Semi-Trailers up to 60 Pallets

3D Render | Box Van Lifting Deck Longer Semi-trailer In Showroom

Longer Semi-Trailers (LSTs) are now permitted for use on UK roads under the amended Special Types General Order (STGO). While they do not fall within type approval regulations, they are lawful to operate domestically in Great Britain when used in line with the STGO framework. LSTs are up to 2.05m longer than a standard 13.6m semi-trailer, extending the total length to 15.65m. This additional space enables them to carry as many as 60 UK pallets, delivering around a 15% increase in volume compared with standard-length trailers.

LSTs are particularly effective for light and medium freight operators, where the extra capacity can translate into:

Reduced delivery frequency: fewer trips needed to move the same volume of freight.
Fuel savings: greater efficiency through reduced mileage.
Lower CO₂ emissions: supporting more sustainable transport operations.

For operators looking to maximise fleet capacity, efficiency and sustainability, Longer Semi-Trailers present a compelling solution.

Are LSTs Legal Yet?: Learn about the legal framework and operating requirements for LSTs.
Longer Semi-Trailers Finally Roll Out: Explore the nationwide rollout and industry adoption.
LSTs: Steering Towards the Right Specification: Guidance on specifications and design choices to ensure operational compliance.

Operating LSTs On UK Roads

From 31st May 2023, Longer Semi Trailers can be operated on UK roads.

An amended Road Vehicles (Authorisation of Special Types) (General) Order 2023 permits operators to run LSTs on pre-planned routes with some operational caveats.

The Longer Semi-Trailer trial, which ran from January 2012, ended on 29th February 2024.

Quick Guide To LSTs

Trailer length may be up to 2.05 m longer than a standard UK semi-trailer
Maximum overall vehicle combination length must not exceed 18.55 m under any circumstances
The 18.55 m limit includes the tractor unit, meaning aerodynamic or extended cabs permitted under Directive 96/53/EC Article 9a cannot be used in combination with an LST trailer if this length is exceeded
Trailer must be tri-axle
A rear steer axle is required to minimise tyre scrub
The combination must physically comply with turning circle requirements (swept path within a corridor of 5.3 m to 12.5 m radii)
Vehicles must continue to operate within the existing UK maximum gross vehicle weight of 44 tonnes

Key Features & Options

Don-Bur engineered their first 16m trailer in 1999 with an active rear steer system (SCM). Since the DfT announced the LST scheme in 2011 Don-Bur has manufactured numerous designs to suit requirements.

Straight, Step-Frame or "Wedge" chassis
Double Deck & Lifting Deck options
Variable length up to 15.650m
Self-tracking or positive steer rear axle configurations

360 Viewer

Take a virtual walk around in our 360 panoramic viewer.

Scene menu buttons on the left of the viewer window allow you to navigate around the trailer to look at specific features.

Example shown is a wedge chassis design with full-length lifting deck platform.

Additional Capacity

15.650m long LSTs can carry up to 4 additional pallets on single deck trailers and 8 additional pallets on double decks (based on UK Pallets 1200x1000mm). This can potentially reduce your deliveries by up to 1 in every 6.5 trips.

Don-Bur can achieve the same double deck height apertures as their standard length couterparts.

Due to the extra length, unladen trailer weight does increase slightly so we advise caution when calculating your GVW.

General Arrangement Drawing

The diagram shown is an example GA for a curtainsider, straight-frame Longer Semi-Trailer (LST) at 4.2 m overall height. Dimensions can be tailored to suit individual operator requirements, including deck height, body length, axle configuration and apertures.

The preview image shown is a low resolution JPG version. The downloadable PDF provides the full, high-resolution technical layout including side elevation and plan-view measurements.

Download the LST General Arrangement drawing (PDF)