Semi-trailer dimensions: the rules around the 13.62-metre deck

Two curtainside semi-trailers from different factories publish the same deck length. Krone publishes a load compartment length of 13,620 mm for the Profi Liner. Schmitz Cargobull publishes an internal body length of 13.62 m for the S.CS Universal. That number does not appear in Council Directive 96/53/EC. What the Directive supplies is a boundary, and it is drawn at the kingpin rather than at either end of the semi-trailer.

The dimensions half of the Directive

Council Directive 96/53/EC also sets weights, and the weight side of it — gross figures, axle limits, the bands that depend on axle spacing — is covered separately in truck weights, GVW and GCW. The title of the instrument draws a distinction that decides this article. It lays down the maximum authorized dimensions in national and international traffic, and the maximum authorized weights in international traffic. In this Directive the weight limits are set for international traffic; the dimension limits reach national traffic as well.

Article 4(1)(a) says so in the negative: member states shall not authorise the normal circulation within their territories of vehicles or vehicle combinations for the national transport of goods which are not in conformity with the characteristics set out in points 1.1, 1.2, 1.4, 1.5, 1.6, 1.7, 1.8, 4.2 and 4.4 of Annex I. Article 4(2) lists what a member state may nonetheless authorise at home — points 1.3, 2, 3, 4.1 and 4.3 — and the only dimensional item on that permissive list is height; the others concern weights. Length and width sit on the first list. That is not the whole of it, because Article 4(4) opens a door in the other direction for certain national operations, and that door is described further down.

Point 1.6 is the rule that bounds the deck

The 16.50 m in point 1.1 is not the deck rule. It is a limit on the articulated vehicle, which Article 2 defines as a motor vehicle coupled to a semi-trailer, so it covers tractor and trailer together.

Point 1.6 is measured on the semi-trailer alone. It fixes a maximum of 12.00 m from the axis of the fifth-wheel king pin to the rear of the semi-trailer. Point 4.4 closes the other end: the distance measured horizontally between the axis of the king pin and any point at the front of the semi-trailer must not exceed 2.04 m. Because it catches any point at the front, that limit works, on our reading, as a radius about the kingpin. Between them the two points describe an envelope of 14.04 m — our arithmetic, a sum printed in neither the Directive nor any maker’s page cited here — inside which, on our reading, the body of a semi-trailer complying with Annex I has to fit, subject to the exceptions the Directive writes for itself, set out below.

Inside that envelope the published figure is 13,620 mm: Krone quotes it for the Profi Liner, Schmitz Cargobull quotes 13.62 m for the S.CS Universal, and Kögel quotes 13,620 mm as the “loading area length clearance” of every Kögel Cargo variant on its product page except the two EuroTrailer variants it labels “long truck type 1”, which it gives 15,000 mm. The Directive does not name the figure, and none of the makers’ pages cited here says how it was arrived at. The 13.62 m deck is published; the 14.04 m envelope is our sum of points 1.6 and 4.4. None of these documents explains the difference between them.

The envelope also bears on what a longer body listing means. Schmitz Cargobull’s own technical data for the S.CS Universal gives two internal body lengths, 13.62 m and 15 m, alongside an internal width of 2,480 mm and 34, 37 or 40 Euro pallet spaces. A 15 m body is longer than the 14.04 m envelope computed above, so on our reading it cannot be an Annex I vehicle. Schmitz Cargobull’s page does not say what legal basis the 15 m body is built for; the Great Britain regime set out below shows what one such basis looks like: up to 15.65 m from the foremost part of the loading area to the rear of the trailer, and a list of conditions attached to it.

Neither of Nooteboom’s two documents on the MCOS semi low-loader gives an overall length for it; what both give in figures is floor height. The MCOS brochure, since removed from Nooteboom’s website and read here as an Internet Archive capture, gave a load floor height adjustable from 810 to 1030 mm. Nooteboom’s current MCO(S) product page lists, among the things the MCOS semi low-loader “is available with”, a “fixed or single extendible load floor” and a loaded floor height of approx. 860 mm in drive position.

Krone’s standard and mega trailers share a plan view

In plan, Krone’s mega trailer is not the bigger one. Krone gives the Mega Liner (type SDP 27 eLG50-CS) a clear side length of 13,620 mm and a clear side width of 2,480 mm — the same two figures it gives as load compartment length and width for the Profi Liner (type SDP 27 eLB50-CS). The dimensions that differ in Krone’s tables are vertical.

The Profi Liner has a front construction height of 125 mm and an unloaded fifth coupling height of 1,050 to 1,200 mm, with a clear side height (lower edge of the external beam) of 2,600 to 2,700 mm. The Mega Liner has a front construction height of 80 mm, a coupling height of 960 to 1,160 mm, and two tabulated clear side heights: 2,595 to 2,845 mm at the lower edge of the external beam, and 3,000 mm on mesh box width. Under optional equipment, Krone says it supplies the Mega Liner with two neck heights, 80 and 50 mm: with a tractor unit at a coupling height of 915 mm the 50 mm neck “permits an internal height of 3,000 mm” — a figure Krone qualifies “UK, roof beam” — and with tractor units at a coupling height of 885 mm the 80 mm neck permits the same 3,000 mm.

Annex I 1.3 sets 4.00 m as the maximum height of any vehicle, and Article 4(2) lets member states authorise national goods vehicles that do not conform to it. Krone’s note ties the Mega Liner’s internal height to the tractor’s coupling height, and Schmitz Cargobull footnotes the S.CS Universal’s internal body height of up to 3,050 mm as “depending on the saddle height and the legal framework conditions”. In both makers’ figures, then, the internal height depends in part on the tractor’s coupling height. Tare weights differ too: Krone’s published dead weight is 5,940 kg for the Profi Liner and 6,350 kg for the Mega Liner, and the first of those two vehicles has a record of its own at Krone Profi Liner.

Krone and Schmitz Cargobull quote the same inside width: 2,480 mm for the Profi Liner, the Mega Liner and the S.CS Universal. That is 70 mm less than the 2.55 m maximum width of point 1.2 — our arithmetic, and a difference none of the three pages breaks down.

The exceptions the Directive writes for itself

The Directive is explicit about where it bends, and the bends read differently once they are quoted in the direction they were drafted. Article 4(3) is a restriction rather than a grant: vehicles or vehicle combinations which exceed the maximum dimensions may only be allowed to circulate on the basis of special permits issued without discrimination by the competent authorities, or of similar non-discriminatory arrangements agreed with them case by case, “where these vehicles or vehicle combinations carry or are intended to carry indivisible loads”. Article 4(5) says member states “may allow” vehicles incorporating new technologies or new concepts which cannot comply with one or more requirements of the Directive to carry out certain local transport operations for a trial period, and “shall inform the Commission thereof”. Article 5, in the wording given by Directive (EU) 2015/719, covers older vehicles and names both of the points this article turns on: articulated vehicles put into circulation before 1 January 1991 which do not comply with points 1.6 and 4.4 are deemed to comply for the purposes of Article 3 if they do not exceed a total length of 15.50 m.

Article 4(4) reaches into the subject most directly, and it is the one most easily quoted by halves. Its first limb is the derogation itself: member states may allow vehicles or vehicle combinations used for transport which carry out certain national transport operations that do not significantly affect international competition in the transport sector to circulate in their territory with dimensions deviating from points 1.1, 1.2, 1.4 to 1.8, 4.2 and 4.4 of Annex I. That range covers 1.6, and 4.4 is named outright, so the two points this article is built on are the express subject of a national derogation. Its second limb is the test: transport operations “shall be considered” not significantly to affect international competition if one of two conditions is fulfilled: either they are carried out in a member state’s territory by specialized vehicles or specialized vehicle combinations in circumstances in which they are not normally carried out by vehicles from other member states, the Directive’s own example being operations linked to logging and the forestry industry; or the member state also permits motor vehicles, trailers and semi-trailers complying with Annex I to be used in such combinations as to achieve at least the loading length authorized in that member state, so that every operator may benefit from equal conditions of competition. The second condition is the modular concept. Both are bounded to national operations, and both are permissions addressed to member states rather than specifications a buyer can order.

Three articles inserted by Directive (EU) 2015/719 show how the drafting distinguishes the length points from each other. Under Article 10c the maximum lengths in point 1.1, subject where applicable to Article 9a(1), and the maximum distance in point 1.6 “may be exceeded by 15 cm” for vehicles or vehicle combinations engaged in the transport of 45-foot containers or 45-foot swap bodies, empty or loaded, provided that the road transport of the container or swap body in question is part of an intermodal transport operation. Article 8b, which covers aerodynamic devices added to the rear, relieves point 1.1 only: it names point 1.6 nowhere, it requires the vehicle to go on complying with the swept circle of point 1.5, and it requires that any exceeding of the maximum lengths shall not result in an increase in the loading length. Article 9a does the same at the front for cabs that deliver improved aerodynamic performance, energy efficiency and safety performance — point 1.1 relieved, point 1.5 preserved, no increase in load capacity. That pair of allowances is examined in aerodynamic cabs and the length rules, and Article 9a also in truck cabs. Of the three, only Article 10c names point 1.6.

What a longer deck requires in Great Britain

The United Kingdom has left the EU, and Great Britain shows one alternative. The Road Vehicles (Authorisation of Special Types) (General) (Amendment) Order 2023, which extends to England and Wales and Scotland, made longer semi-trailers “a recognised category of special vehicles”. Its length requirements move exactly the measurement this article is about: the longitudinal distance from the axis of the kingpin to the rear must not exceed 14.05 m, the distance from the foremost part of the loading area to the rear must not exceed 15.65 m, and the overall length of an articulated vehicle including one must not exceed 18.55 m.

The conditions attached are the interesting part. Such a trailer must have a minimum of three axles, one of which must be capable of steering. Where the maximum authorised weight of a combination that includes one exceeds 38,000 kg, the longer semi-trailer must be equipped with an on-board weighing device. A load must not have a rearward projection. And, save for a diversionary route where use of the established route is prohibited under another enactment or the operator reasonably considers it likely to be subject to unreasonable traffic delays because of an accident or other obstruction, it must not be used on a road otherwise than on an established route, meaning one specified on a written route plan and covered by a written risk assessment. Even that carve-out is fenced: an operator who learns of the prohibition, accident or obstruction before the trailer reaches the established route may not use a diversionary route where it is reasonably practicable to use an alternative established route, or to put the diversion on a route plan and complete a risk assessment for it; and where the cause is a prohibition, the diversionary route “may be used for a period of seven days” from the day the prohibition came into force, unless the prohibition is revoked or expires sooner. In Great Britain a longer semi-trailer is a recognised category of special vehicle with operating requirements attached, not a normal trailer with a longer deck.

The number is on the plate

Article 6(1) requires member states to “take the necessary measures to ensure” that vehicles in scope and complying with the Directive carry one of three proofs, and where that proof takes the form set out in point (a) it includes a plate relating to dimensions, specified in Annex III. Among the data on it are the distance (a) between the front of the motor vehicle and the centre of the coupling device, with minimum and maximum values where the fifth wheel has several coupling points, and the distance (b) between the centre of the coupling device of the semi-trailer — the kingpin — and its rear, again with minimum and maximum values where the device has several coupling points. For a semi-trailer that second figure is the same kingpin-to-rear distance that point 1.6 limits, although Annex III lists it among the data “for the measurement of the length of vehicle combinations”. Under Article 6(2), if the vehicle’s characteristics no longer correspond to the proof of compliance, the member state of registration “shall take the necessary steps to ensure” that the proof is altered.

Checks on dimensions are framed differently from checks on weights: under Article 6(4) a vehicle carrying proof of compliance “may be subject” to random checks on weights, but on dimensions “only to checks where there is a suspicion of non-compliance”.

The revision of the Directive had not been adopted when we checked on 23 September 2026. The Commission proposed it on 11 July 2023, Parliament adopted its first-reading position on 12 March 2024 and the Council agreed a general approach on 4 December 2025; trilogue meetings started on 9 December 2025, and the Legislative Observatory gives the stage reached as “Awaiting Council’s 1st reading position”. Until a new text is adopted, points 1.6 and 4.4 stand as quoted above. Height, tare and body type are compared in trailer types, and set out figure by figure for one worked example in the Schmitz Cargobull S.KO COOL SMART record.