TMC’s trombone semi-trailers are designed for maximum versatility, with extendable deck lengths to accommodate oversized and variable loads. Whether transporting structural steel, roofing, trusses, or heavy machinery, TMC trombone trailers deliver the strength, stability, and flexibility needed to handle long and irregular freight. Available in flatdeck or stepdeck configurations, with fixed or sliding rear bogies, TMC trombones are engineered for reliability, balance, and smooth extension under real-world conditions.
Extendable Deck
Expands to carry long or oversize loads, then retracts for compact transport and improved manoeuvrability, locking positions for different overdimension categories.
Heavy-Duty Construction
Built from high-tensile steel with laser-cut chassis profiles and precision-engineered slide mechanisms for strength, reliability, and smooth operation.
Versatility
Adjustable deck length accommodates a wide range of freight — from steel beams and pipes to prefabricated structures and timber.
Efficiency
Reduces the need for specialised overlength permits when retracted, improving fleet flexibility and utilisation.
Nationwide Service Support & Warranty
Backed by TMC’s own workshops in Auckland, Hamilton, and Christchurch, plus authorised service agents across all main centres. We also operate a full online parts store with fast nationwide delivery of genuine TMC trailer components, keeping your fleet moving with minimal downtime. Every TMC trailer is covered by our 2-year, unlimited-kilometre warranty, giving you total confidence and support long after delivery.
Chassis & Deck Options
Thin-neck or step-deck chassis for variable fifth-wheel heights or lower load decks, High-tensile steel or shiplapped hardwood timber deck s, in-deck chain boxes, container locks, longitudinal deck stiffeners for trolley jacks and vehicle transport, rear wind-out extensions and sidelifter footpads.
Headboards & Load Retention
RHS open-style, steel-plated, or fold-down headboards, upright stanchions, heavy-duty stanchions for pipe or concrete work, and trestles/crossbars for specialised freight.
Running Gear & Suspension
Axle and suspension options from ROR, Jost, SAF, BPW, and Hendrickson.
Fixed or Sliding Bogie Options
Fixed bogies are standard; sliding bogies are available for operators running multiple tractor setups or mixed load lengths.
Wind-Out Rear Extensions
Optional rear frame extensions ensure rear lighting remains visible beyond the load.
Guards & Accessories
Plastic or polished aluminium full guards, with stainless infill strips between ribs, toolboxes, dunnage boxes, and cover boxes available as well as overwidth signage, spare-tyre carriers, and strap-stowage racks.
Under New Zealand’s Vehicle Dimensions and Mass (VDAM) Rule, a standard tractor-and-semi-trailer combination can be up to 19 m long. With a High Productivity Motor Vehicle (HPMV) permit, this can extend to 19.45 m, and gross combination mass (GCM) can rise to roughly 39–41 tonnes depending on the axle layout and approved route.
If a trailer extends beyond those standard limits, it’s classed as Overdimension and must meet the NZTA Overdimension requirements. These rules define how oversize vehicles operate on public roads and what warning or pilot arrangements are needed.
Category 1 applies to vehicles over the standard limit but under 25 m (no pilot needed below 40 km/h). Category 2 covers 25–35 m vehicles, which often need 1–2 pilots, hazard panels, and restricted travel times. Categories 3 and 4 apply to units 35 m and longer, requiring NZTA / OPIA permits, route approval, pilot escorts, and sometimes engineering certification.
👉 Learn more: NZTA Factsheet 53 — Overdimension Vehicles and Loads
✅ Lower tare weight – fewer rims, tyres, and bolts reduce overall trailer weight
✅ Less rolling resistance – improves fuel economy and slightly reduces CO₂ output.
✅ Simpler maintenance – only one tyre per hub to check and replace.
✅ Better tracking – fewer scrub forces on corners, reducing tyre wear on tri-axle setups.
19.5” Dual Tyres
✅ Higher load tolerance per axle – twin tyres spread the weight, ideal for heavy or uneven loads.
✅ Redundancy – if one tyre fails, the other can support the axle temporarily.
✅ Lower deck height – smaller diameter tyres reduce overall trailer height.
TMC trailers are backed by nationwide after-sales support through our own workshops in Auckland, Hamilton and Christchurch and authorised service agents in all main centres. Our team provides warranty repairs, servicing, and genuine parts to keep your trailer on the road and performing at its best.
All new TMC trailers include a free 5,000 km service check, ensuring everything is running perfectly after delivery.
We also operate a full online parts store with hundreds of trailer components — from axles and suspension parts to lights, mudguards, and hardware — all available for fast delivery across New Zealand.
👉 Shop online: tmc.kiwi/parts
Every TMC trailer is supported by our 2-year, unlimited-kilometre warranty, giving you complete confidence long after delivery.
With over 77 years of experience, TMC is proudly New Zealand owned and operated, delivering trailers built for Kiwi conditions. Our nationwide service network and proven reputation mean you get support wherever you are—and performance you can trust. Join the many operators who rely on TMC to keep their business moving.
Engineered for NZ, designed to perform – not just to comply
With 3 generations of experience, we know what works and doesn’t
Nationwide support backed by the best warrant in the industry
Trusted by NZ’s biggest transport companies and local operators alike
