Guide to longer semi-trailers (high-volume trailers)

04 November 2011
By admin

At the start of October 2011 the Department for Transport (DfT) confirmed it would allow the use of 1,800 longer semi-trailers on UK roads in the form of a ten-year pilot starting in 2012.

The pilot will see 900 semi-trailers (or high-volume trailers as the government is now calling them) at an increased length of 2.05m, and 900 trailers at an increased length of 1m (over the current 13.6m maximum) hit the roads. These will operate under Vehicle Special Orders (VSO), but despite this status they will still be expected to under go annual road worthiness checks.

Under the trial there will be no increase in the current maximum gross vehicle weight of 44 tonnes. However, in an unexpected decision, the DfT confirms that within these length and weight stipulations operation of double-deck trailers will be allowed.

The DfT will cap the number of trailers operators can run to ensure fairness, but it will not provide compensation if the trial is cancelled early. While some observers think this a real possibility it should be noted that Germany has in effect been running a perpetual trial of longer trailers since 2006.

An independent contractor will conduct four-monthly assessments covering the operational safety, manoeuvrability and economy of the longer trailers. The DfT will publish an annual review of the pilot on its website.

Apply to take part

The DfT is asking for submissions of interest to take part in the pilot. It promises an as yet undisclosed formula for applications that will be fair and transparent, making sure all operators are given a chance to take part in the pilot irrespective of size. It has issued guidance for applicants, which includes the appropriate expression of interest forms. The initial deadline is 2 December and the trial is open to own-account operators and hire and reward, as well as leasing companies as long as they can identify the operator they plan to supply. Expressions of interest need not be for immediate introduction and the DfT, which will advise operators in January on the outcome of their applications, has added that it does not intend to allocate the full quota in one hit.

The information required includes:

1. For operators

number of semi-trailers in current fleet.

number of trailers for which VSO sought.

2. For all applicants

dimensions of trailers sought (e.g. single-deck 14.6m; high cube 15.65m; double-deck 15m).

purpose for which trailers will be used.

· Timeframe over which trailers are expected to be brought into operation

· Indication of whether applicant would be interested in trialling active steering technology.

The trial

Successful applicants will be asked to sign an ‘operator’s undertaking’ agreement with the DfT to ensure longer semi-trailers are presented to VOSA for annual tests; to provide quarterly data to the independent reviewing body; to mark any confidential commercial data supplied to the DfT as such; and to inform the secretary of state for transport if a longer semi-trailer is involved in a serious accident. The trial itself will be used to identify additional costs and benefits not addressed in the impact assessment, including effects on infrastructure. It will also identify any technical and legislative development necessary to ensure advanced active-steer axle technology can be fully assessed and deployed on new trailers.

Basic technical requirements for the trial are:

1) The overall length shall not exceed 18.55m.

2) The distance from the axis of the king pin to the rear of the semi-trailer shall not exceed 14.05m

3) No point in the semi-trailer forward of the transverse plane passing through the axis of the king pin shall be more than 2.04m from the axis of the king pin.

4) The maximum distance measured parallel to the longitudinal axis of the semi-trailer from the foremost point of the loading area to the rear of the trailer shall not exceed 15.65m.

5) The semi-trailer shall be equipped with three axles.

6) Any semi-trailer equipped with axles that employ a steering arrangement shall be constructed such that the steering system is locked in the straight ahead position at speeds exceeding 31mph, or be designed in such a way that locking is unnecessary.

The trailer manufacturers

The major trailer manufacturers are all set to make longer semi-trailers available to operators.

Cartwright Group has designs in place ready for manufacture, with director John Cartwright adding: “We’ve been making longer trailers here for some time for the likes of BAE and Airbus.” It plans to build longer semi-trailers not only for sale but also rental.

Don-Bur, which has been working closely with Wincanton to design its first 16.65m long teardrop pillarless tri-axle in readiness for the trial, believes it will provide 15% additional load capacity or four extra pallets.

Ahead of the pilot announcement Lawrence David was working to re-design its pillarless curtainside trailer design and expects the first to be ready for demonstration “imminently”. It has three designs that fit the criteria demanded: a 15.65m with two tri-dec command steer system for curtainside of box; and a 15.65m with rear steer system for curtainside or box (limited to 42 tonnes).

SDC, which has worked closely with Eddie Stobart to develop longer trailers has 14.55m self-steer, 15.65m self-steer and 15.65m dual-steer options on offer. MD Mark Cuskeran says: We have adapted the factory to deal with the longer trailers and have the capacity to build trailers quickly for those companies who are successful in applying for trial certification.”

Muldoon Transport Systems has already been operating a 15.65m trailer under a VSO in Northern Ireland for the past two years. It states it is ready to supply as and when necessary.

Consultation results

The DfT has also published the results of the longer semi- trailer public consultation, which presents insights from operators, manufacturers and trade associations.