Review: Joskin Trans-Cap dumper silage trailer

By: Mark Fouhy, Photography by: Mark Fouhy

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In farming and contracting, as a generalisation, bigger is better. However, after testing a Joskin Trans-Cap dumper silage trailer from OriginAg, Mark Fouhy is reminded of Goldilocks and getting things ‘just right’


 Arriving north of Paeroa on New Zealand’s North Island to catch up with the team from RK Flint Contracting, we found one of its larger loader wagons wedged between two gateways, with the other trailers arriving and slowing down the flow of maize to the stack. Our Joskin test machine, however, quickly found an alternative way to the pit: backed up, dumped and was away again for the next load.

As a standard bathtub design, the Trans-Cap has a capacity of 15.5 cubic metres and is rated to a total of 14 tonnes. With side extensions, an extra 13.2 cubic metres can fit per load to give a total capacity of 28.7 cubic metres (or around 29.1 cubic metres heaped).

The big question is: how do these trailers tow? Both the main contracting driver and I were in complete agreement – it tows bloody fantastic! Anyone who has done any tractor and trailer silage hauling will no doubt have had their share of horrible trailers, ones that bounce when unloaded or loaded and rattle and shake so you can hear them coming across the county.

There was absolutely none of this carry-on from the Joskin Trans-Cap trailer. Some of this is down to the simple leaf spring on the drawbar. This runs across the trailer – a proven design I’ve seen used on the Joskin slurry tankers in the past. The tandem axle is running a basic (heavy-duty 18 tonnes) ADR rocker beam bogie. The Joskin bogie is a bolt-on unit, which allows adjustment to balance the weight between the trailer, hitch point and tractor for added traction. Joskin assembles its own bogies so each is personalised to suit that specific machine.


Standard on quality BKT 560/45R22.5 rubber, this was one area Flint Contracting would spend some extra dollars – investing in wider tyres to compensate for the fact that they frequently operate on peat country. However, in many cases, changing to wider tyres also means they are slightly taller, too.

At its present set-up, the Joskin Trans-Cap is narrower than the John Deere 6215 pulling it, making it straightforward going through gates with the 2.5-metre-wide trailer fitting easily. No stuck trailers with this model. With a bin length of 5.5 metres and an overall length of 7.2 metres, it’s fairly compact with minimal tail swing when turning off narrow roads or laneways into small gateways (which are still relatively common).

Tipping at the pit was a quick affair. With a single-stage ram, the trailer is tipped to a maximum 50.1 degrees and back down in no time. A parachute safety valve is fitted that requires counter pressure and prevents it just slamming back down, should the hydraulic hose ever blow off.

A flashing rear light is wired to the tractor headlights

An oscillating cradle allows movement of the ram forward and rear as well as left to right. This reduces stress to the chassis. There are pluses and minuses of single or twin lift rams. The single ram gives quick operation with low hydraulic oil flow requirement and a smooth, even drop. It also keeps the chassis of the trailer narrower, allowing options for wider tyres, while staying within road requirements for width.

Standard equipment for these trailers is four-wheel hydraulic brakes, with air brakes an optional extra. Road lights are also standard. Mounted on rubber, they are designed to flex and move out of the way rather than breaking. Also, the rear flashing light is wired into the main lights of the tractor, so it automatically turns on with the tractor lights.

For loading, there’s a perspex front window, protected by metal bars to help with improved vision for seeing what’s going on around you. If you should need to climb into the tub, there’s a ladder to get in and steps to get out. The hydraulic locking rear tail door has a rubber seal so grain won’t escape, and it should also hold water so might make a good pool on hot summer days. The side extensions are two pieces: 250mm and 750mm. Being alloy, it isn’t a big job to remove these when you want to change jobs.

The leaf spring drawbar suspension works well


Joskin has been producing agricultural equipment since 1968 and the range of slurry tankers has long proven its popularity with farmers and contractors, and the trailers look set to continue this tradition. It’s great to see the addition of the Joskin Trans-Cap to the range – a truly multi-purpose machine aimed at the farmer/ contractor. The fact this trailer is still in bathtub form means you get the added strength of the bathtub design.

The Joskin factory is advanced, with robotic welding of the tubs to ensure the quality of the job is 100 per cent right every time, it states.

The steel used is 4mm, whereas some other brands are using 3.5mm for a similar capacity trailer. With a rolled bottom, there are no corners for partial load to get stuck. Although hard to tell just by looking, the bin has a small taper. Again, this is to help release the load for quick, efficient and safe dumping.

The finish of the Joskin trailer is A1. The two-pack paint system used is done to the same standard as a tractor or lorry to keep machines looking good for years. Painting is completed before final assembly of the different components.

Perspex front frill to help monitor loading progress


The ability to offer such a variety of options means each trailer can be customised for specific requirements. Our test machine for the day was the basic standard issue, and there’s no denying it gets the job done.

Options such as larger tyres, remote greasing or full auto greasing and load covers can easily be added (albeit with extra cost as with all brands).

The Joskin Trans-Cap 5500 works well and suits the 180–220hp (134–164kW) tractors operated by most contractors. If you were after something larger or smaller, it would need to be ordered, and then you can add whatever extras you liked direct from the factory.

High-lift tall door for easy dumping


It’s great to see this multi-purpose addition to the Joskin line-up. The fact that it’s not limited to being a one-trick pony and can be used for a range of tasks makes it a worthy contender when considering purchasing a new trailer. Although grass and maize silage are almost done for the season, the ability to keep the trailer busy during the off-season hauling metal and soil would help justify the expense, or at least that’s what you could tell the accountant. Efficiency in having the right machine for the job helps drive productivity.

The Joskin Trans-Cap is not the cheapest option on the market, but as anyone who has bought gear and relies on it for productivity knows, it’s worth paying more for top quality, which is built to both perform and last.

An impressie tipping angle of 51 degrees

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