Low Loader & Heavy Haulage Transport Guide
Moving heavy or oversized machinery by road requires more than a big truck. Permits, route surveys, escort vehicles, and lashing calculations must all be right before a wheel turns — and mistakes are expensive.
Deck height
400–900 mm
Max payload
up to 150 t
Extendable deck
up to 30 m
Permit required
Above 44 t GVW
Low Loader Type Selector
Select a trailer type to see deck height, payload capacity, typical cargo, and permit requirements
Deck height
400–550 mm
Max payload
60–80 t
Deck length
12–14 m fixed
Permit class
STGO Cat 1–3 depending on weight
Continuous low deck from front to rear. Best for wide, heavy machinery that needs a uniform loading surface — construction plant, transformers, generator sets. Lowest deck height of any trailer type.
How to plan and execute a heavy haulage shipment
Heavy haulage requires advance planning that begins weeks before the transport date. Route surveys, permit applications, and escort coordination cannot be rushed — every country on the route has its own requirements.
Step 1
Classify the load — determine weight, dimensions, and indivisibility
The starting point is always the cargo specifications: gross weight (including any lifting frames or skids), length, width, height, and centre of gravity position. A load is classified as 'abnormal' when it exceeds standard road legal limits — in the EU, this typically means over 44 tonnes GVW, over 2.55 m wide, over 4.0 m high, or over 18.75 m overall length. Crucially, permits for abnormal loads are only available for indivisible loads — cargo that cannot be separated into smaller pieces without disproportionate cost or risk. A shipment of ten machines that happen to be heavy does not qualify as an indivisible load; a single transformer or turbine does. Document the indivisibility of the load — some permit authorities require written evidence that the load cannot be broken down.
Step 2
Select the correct trailer type for the cargo
Low loader selection depends on three factors: deck height required (to keep overall height within permit limits), deck length, and axle configuration. Standard low loaders (400–550 mm deck) are ideal for tall equipment like excavators and transformers where every centimetre of height matters. Step-frame trailers suit cargo that is tall at the front but lower at the rear, or cargo that must be driven up rather than craned on. Extendable trailers are essential for cargo longer than 14 m — wind turbine blades, bridge beams, or ship sections. For very heavy loads (above 80 t), modular platform trailers (MPTs or SPMTs) with multiple steerable axle lines distribute weight across more axles and allow free-form configuration around any load shape. Weight per axle line must not exceed the road-legal limit — typically 10–12 t per axle in most EU countries.
Step 3
Commission a route survey and apply for permits
A route survey identifies obstacles that prevent or restrict the planned movement: low bridges, overhead cables, traffic lights, roundabout radii, weight-restricted sections, and level crossings. For loads above certain thresholds, a formal route survey report is required by the permit authority. Begin permit applications as early as possible — transit country permits can take 4–8 weeks, and some countries process permits sequentially (the next country's permit cannot be applied for until the previous one is granted). Permits specify the exact route, permitted travel times (often restricted to nighttime or weekdays only), maximum speed, and escort requirements. Never deviate from the permitted route without contacting the relevant authority — an unpermitted deviation voids the permit and can result in prosecution.
Step 4
Calculate lashing forces and secure the load
Load securing for heavy haulage is governed by the same EN 12195 standard that applies to standard trucks — but the forces involved are much larger. For heavy machinery, the primary securing method is direct lashing through lashing points built into the cargo or its transport frame. The total lashing capacity must cover 100% of the cargo weight in the forward direction and 50% sideways and rearward. Calculate the required number and angle of lashing chains based on the cargo weight and the dip angle of each chain. For very heavy or oddly shaped cargo, a specialised rigging engineer may be required to calculate the lashing plan. Block and brace using timber or steel wedges to prevent any possible movement — even a shift of a few centimetres on a moving low loader can cause catastrophic instability.
Step 5
Arrange escort vehicles and notify authorities
Escort requirements vary by load size and country: in many EU countries, loads wider than 3.5 m require a front escort; loads wider than 4.5 m typically require both front and rear escort plus police involvement. Escort vehicles must be equipped with flashing amber lights, 'ABNORMAL LOAD' signage, and radio communication with the haulier. Some countries require pilot cars to carry height gauges, measuring rods, and first-aid equipment. For loads that travel through multiple countries, escort requirements must be checked country by country — what is legal in Germany may require additional escorts in Austria or France. Notify utility companies (electricity, telecoms) at least 5 working days before transport if the load height is close to or above overhead line clearances.
Step 6
Execute the move — timing, communications, and contingency
Most heavy haulage moves are restricted to specific time windows: often Monday to Friday, avoiding rush hours, and sometimes limited to nighttime for the widest or tallest loads. Brief the entire convoy before departure: establish radio channel, convoy speed, stopping distances, and the procedure if an obstacle is encountered en route. Carry a copy of all permits, the route survey, the lashing calculation, and the cargo specifications in the cab. If the load must stop — for a break, a traffic incident, or a permit issue — ensure the stopping point is safe and does not block traffic unnecessarily. Have a contingency plan for an unexpected obstacle: know which permit authority to call and what the alternative route options are.
Heavy haulage permit rules at a glance
Based on EU Directive 96/53, UK STGO, and individual country-level abnormal load regulations. Permit thresholds and requirements vary by country — always verify with the local authority.
Standard EU width limit
2.55 m
Above this = permit required
Standard EU height limit
4.0 m
Some countries allow 4.3 m
Standard EU GVW limit
44,000 kg
5-axle semi-trailer
Max axle load
11,500 kg
Per single drive axle
UK STGO categories — self-authorisation thresholds
Three categories of increasing weight
In the UK, the Special Types General Order (STGO) defines three categories of abnormal load that do not require a full Special Order (police escort and authority consent): Category 1 covers vehicles between 44 t and 80 t GVW — the operator must notify the police and local authorities at least 5 clear days before movement. Category 2 covers 80 t to 100 t — same notification requirement plus a mandatory attendant (escort) vehicle. Category 3 covers 100 t to 150 t — notification plus two attendant vehicles. Above 150 t GVW, a full Special Order from the Department for Transport is required, with individual route consent from each local authority on the route. STGO categories also impose speed limits: Cat 1 — 60 mph max on motorways, 40 mph on other roads; Cat 2 — 50 mph motorways, 35 mph other; Cat 3 — 40 mph motorways, 30 mph other.
Route survey requirements
Mandatory for most abnormal loads
A route survey is a physical inspection of the planned route to identify any obstacle that could prevent or restrict the abnormal load movement. For loads above typical permit thresholds (usually width >3.5 m or height >4.5 m), most permit authorities require a route survey report produced by a qualified surveyor. The survey checks bridge clearances and load ratings, overhead cable heights (electric, telecoms, rail catenary), roundabout and junction geometry, road width at pinch points, turning radii at intersections, and the condition of verges where the load may need to swing wide. Many route survey companies offer satellite route analysis as a first step — but physical surveys remain mandatory for the heaviest or largest loads. Utility companies must be notified and may need to temporarily raise or disconnect overhead cables.
Escort and pilot car requirements
Mandatory above 3.5 m wide or 4.5 m high
Escort (or pilot) vehicles accompany abnormal loads to warn approaching traffic, stop at junctions, and handle obstacles. Requirements vary by country and load size: in Germany (Großraumtransport), loads wider than 3.0 m on motorways and 3.5 m on other roads require an escort vehicle. In France, a front escort is mandatory above 3.5 m width; above 4.0 m, both front and rear escorts are required. In the UK under STGO Cat 2–3, an attendant vehicle is mandatory. Police escorts are required for very wide (above 4.5–5.0 m) or very heavy loads in most countries, and they impose a specific travel window and route. The escort driver must be trained in abnormal load procedures and carry the required equipment — do not use an untrained driver with a sign-written car as an escort vehicle.
Frequently Asked Questions
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