SDC Trailers was established 45 years ago by welder and fabricator Seamus McCloy in a tin shed small unit beside his house in the village of Bellaghy, Northern Ireland.


SDC Freespan

The firm grew rapidly and in 1982 McCloy acquired his first factory in nearby Toomebridge, Co Antrim. This site is known today as Plant 1 and is home to the group’s headquarters. In 1982 there were 17 full time employees, today there are nearly 900, and with a turnover of over £180m in 2021, SDC Trailers remains the UK and Ireland’s largest trailer manufacturer.

Paul Bratton was appointed group president of SDC in 2020 when former CEO Enda Cushnahan decided to move on after 23 years with the company. Apart from brief spells with a couple of competitors, Bratton has worked for SDC even longer, becoming a director in 1996 after starting his career as a welder with Neville Charrold.

1985 was a watershed year, as that is when SDC built its first curtainsider for Miller Transport, and in that year, there were a total of 20 new curtainsiders built. This is SDC’s most popular product and in 2023 built 4,000 curtainsiders out of a total output of 6,500 units, as volumes have not yet returned to pre-Covid levels.

“We were planning to build 7,000 but a combination of labour and materials shortages meant we lost a bit of production,” says Bratton. “At the staff’s request we have gone to a four-day week, so they do 41.5 hours Monday to Thursday and overtime on a Friday. That suits us as we don’t have to open the factory on a Saturday but it is still difficult getting people to do the overtime.”


Paul Bratton

Bratton says that despite the uncertain economic outlook for 2024, hauliers have not been cancelling orders – except for one 15.65m longer semi-trailer (LST).

In 2012 SDC led the development of LSTs when the UK government started a 10-year trial of 1,800 14.6m and 15.65m trailers, and it was the first company to manufacture the longer length trailers that allowed operators to carry greater volumes, resulting in lower fuel costs and emissions.

In 2023 the DfT ended the trial but imposed onerous restrictions on the operation of LSTs which has seen many operators park them up and stop ordering new units. The DfT has since reversed this decision and extended the trial once again.

“Innovation comes from legislation, such as LSTs,” says Bratton. “But now we are encumbering ourselves with unnecessary administration. The trial was successful, but customers have put a hold on ordering any more.”

1994 saw the acquisition of Neville Charrold in Mansfield, Nottinghamshire, giving the firm a foothold on the UK mainland as well as a range of high quality tipping trailers. Two years later the plant was expanded from 15,000sq ft to 70,000sq ft.

The demand for SDC trailers and the creation of its Truck and Trailer Parts division resulted in a new plant being built at Toomebridge in 2006. This facility, known as Plant 2, is just across Deerpark Road from Plant 1 and is home to the parts branch, repairs and graphics workshops. Plants 1 and 2 now total over 300,000sq ft of manufacturing space, and group wide the company has 500,000sq ft of factories.

In June 2016, CIMC Vehicles, the Chinese number one global trailer manufacturer, acquired SDC’s parent Retlan Manufacturing Group. CIMC, founded in 2002, is a leading trailer manufacturer with a presence in Europe, North America, Latin America, Asia, Australia and Africa. The company is a subsidiary of CIMC Group based in Shenzhen which has turnover in excess of $10bn (£7.7bn) and almost 70,000 employees. The group also includes Vanguard and CIE in the US, GTS Trailers in Australia and Belgium tanker builder LAG, whose products are distributed in the UK by Williams Tanker Services.

Since the acquisition, SDC has continued to invest heavily in its factories to increase production capacity and product quality. In August 2018 it completed a £7m expansion to Plant 1, creating 50 new skilled jobs and boosting output to meet increasing demand.

“Many UK trailer builders have been bought by various investors of whatever nationality and we have benefited from Chinese ownership from an engineering point of view,” says Bratton. “They are selling 40,000 units a year into the US so we are able to benefit from that experience.

“They are certainly not sleeping investors. We have recently opened a new factory in Southampton which is bringing in skeletal trailers from China and assembling them. That has been hugely successful. They are to an SDC design and they will test it on their rigs before building them.

“They use robot welders, which are fascinating to watch, and they make 130,000 trailers a year in China.”

Around 40% of SDC’s output leaves the factory with a body fitted, and its trailer range features 500 different variants spanning curtainsiders, boxvans, skeletals, platforms and urban trailers.


SDC holds to the principle of  for their particular operation, unlike some of its continental European rivals which produce high volumes of standardised products. That includes being able to specify dimensions, flooring, tyres, axles, curtains, roof and doors to exactly suit the application.

“I walked down the production line last week and there were not two trailers the same,” says Bratton. “Two were for the same haulier but they were for slightly different jobs.”

This drive to give the customers what they need rather than producing standard designs, coupled with the UK’s ability to run up to 4.9m high doubledecks, has contributed to a thriving yet highly competitive domestic trailer building industry.

“I love the fact that we have managed to keep the Europeans out,” says Bratton. “We are technologically so superior to Europe.”

One of SDC’s most popular products is the pillarless Freespan curtainsider which has the high tensile steel body bolted on to a robotically welded chassis. The design uses a low friction allow roof rail that makes the EN-XL certified curtains easy to pull.

“We sell more of that than anything else,” says Bratton. “It has been fantastic for us.”

Around 20% of SDC’s curtainsider trailers are fixed doubledecks. It stopped making moving decks as demand for these more complicated vehicles dwindled.

“We are trying to concentrate on what we do well rather than branching out into other products,” says Bratton. “We have done car transporters before but there are 1,000 engineering hours in those and we don’t have that capacity.

“In China they have a huge facility building refrigerated trailers, but we won’t bring them to the UK as there are already well-established players in that market. It is a battle I am not prepared to have, not least because we build a lot of chassis for other people.”

A growing UK labour shortage means SDC’s design engineers have to keep one eye on the buildability as well as the performance of their products.

“It is quite disappointing that young people aren’t coming through the door to learn,” he says. “Our two apprentices are both relatives of existing employees. We had to stop making tippers because we couldn’t get anyone who could weld aluminium.”

As tractors become more complex and heavier, operators are looking to trailer builders to shave weight without affecting durability and reliability - this is before battery electric tractors that will be even heavier take to the roads.

“Everyone is wanting lighter trailers once again,” says Bratton. “The trucks are getting heavier because of increasing emissions control systems so they say to us ‘make the trailer lighter!’”

Back in 2016 SDC together with brake manufacturer ZF launched the world’s first prototype kinetic energy recovery system (KERS) semi-trailer. This was said to deliver a reduction in fuel consumption of up to 25% by capturing electrical energy during vehicle deceleration in a bank of graphene ultra-capacitors.

“The KERS trailer is making a comeback,” says Bratton. “Everyone has forgotten about it but the technology has moved on so much further. The problem is most of our trailers go from factory to RDC and the driver only uses the brakes twice. So the initial trials weren’t that successful.

“But if the trailer can contribute to the efficiency of the truck, it might be appreciated more now.”


One area of improved efficiency that has proved tricky however is the use of long life, low energy LED lamps on trailers. Most trucks now have tell-tale warning lights on the dash which come on if a lamp fails. The problem is that an LED lamp has such low resistance it looks like a failed lamp.

“It lights up as a trailer fault because there is no resistance,” says Bratton. “So 80% of our trailers still have bulbs in the rear lights. It is ludicrous that all these years after LEDs came in, we are still fitting bulbs.”

The manufacturer has a policy of not competing with trailer rental companies and so enjoys a solid working relationship with the leading UK and Irish trailer rental companies. Around half of SDC’s new trailer business is with rental firms, making this an important customer base.

“They have all diversified into funding so a failed trailer builder would no longer be left with contingent liabilities on their balance sheet,” explains Bratton. “The finance or leasing company will take that now because they have the facility to get a second life from that trailer.

“So a customer will now place an order with us and give us instructions from one of what I would call the big three rental and leasing companies. They now have all the data and that is why we are still predominantly drum brake. If you park up your trailers, discs aren’t the answer.

“They know almost to the kilometre when a hub will need replacing so they can price that in.”

Bratton says he loves the UK transport industry and has made many lifelong friends in his 33 years in the industry. A keen cyclist, he is a regular on TIP MD Mike Furnival’s charity bike rides, which last year raised £93,111 for the Douglas Macmillan Hospice in Staffordshire.


Used trailers struggling to find buyers

The used trailer market is “on its backside”, says Bratton. “You can’t give them away at the moment”.

He says the situation has been created by changes to capital allowances which has made it more cost effective to buy new trailers - even though they are 25% dearer than before Covid-19 – than buy and refurb used vehicles.

“That’s great for us but there used to be lots of outlets for used trailers that aren’t there any more,” he says. “We have refurbishment facilities in Northern Ireland and Mansfield but we have drawn down the Mansfield one to give us more space to build new trailers.

“If you buy a new trailer for £30,000 and your used curtainsider is only worth £1,500 are you going to spend £1,000 on a new set of curtains and £3,000 repainting and restoring it? Probably not.”

The steel chassis might be worth recycling as the price of new steel continues to rise, but there is a lot of labour involved in stripping a used semi-trailer back to bare metal.

“A plywood floor is easy to take out but Keruing hardwood can be a problem,” says Bratton. “Aluminium from the roof rail is sought after but no one knows what to do with the tyres.”


Tyre pressure monitoring coming for trailers

Under Regulation 141 of the next set of EU General Safety Regulations (GSR 2) coming into force in July 2024, a tyre pressure monitoring system (TPMS) will be mandatory across all axles of heavy trucks and trailers. This poses particular problems for trailer builders who have no idea what system will be fitted to the various tractors that could be hauling their semi-trailers.

TPMS can be direct systems using sensors mounted inside each wheel to measure the tyre pressures and send the data via radio to a control unit or indirect which, like most cars, use the vehicle’s ABS sensors to compare the rotational speeds of the tyres to detect pressure loss.

Both types must warn the driver in real time of any pressure loss.

“We’ve got a system that uses a sensor fitted inside each tyre that communicates to a box which in turn links to a Haldex, Wabco or Knorr-Bremse braking system,” explains Bratton. “Those are the three we would use on our trailers. The tractor unit will then pick up on that information from the electronic braking system.

“Even if a fitter takes the tyres off and puts them back in a different order it will sense that. Operators need a system which is simple and cost effective.”