Review: SlurryKat SDT 25

By: Dan Reymer, Photography by: Dan Reymer

The SlurryKat SDT 25 is a well-designed trailer suited for NZ conditions.

The pristine quality of SlurryKat design and manufacture

Having a solid trailer that can haul heavy soils and rubble is becoming a necessity around the country as more and more contractors keep themselves busy during the off-peak period. Contractors, whether civil or agricultural, want a robust and versatile trailer they can keep busy when their main work slows down.

With this in mind, Gavin Brownrigg from Brownrigg Agri Gear had a silage, dump trailer (SDT) custom-designed and built by SlurryKat in Ireland, to meet the high demands of the New Zealand industry. With many trailers on the market that are purely dump trailers, silage trailers, or grain trailers, Brownrigg’s SlurryKat SDT brings a heavy-duty dump trailer into the silage category, which gives civil and agricultural contractors alike an opportunity to expand their operations without investing in additional pieces of equipment.

We take a look at the second generation of SlurryKat SDTs to come into the country and see how well it performs in the paddock.

Minimal soil disturbance thanks to thoughtful design


SlurryKat has earned itself a respected name for manufacturing high-quality equipment that’s built to stand the test of time. Having the ability to test their own machines in the field through the contracting side of the operation is a huge advantage. This allows a constant overview of how the machines perform practically with all the challenges of real-life contracting thrown at them, allowing for any design improvements.

The SlurryKat SDT has been engineered to handle the most demanding trailer tasks, and the design makes it simple to change between silage and dirt.

Being made completely out of Hardox S700, the strength of the steel is second to none, assuring the durability of the trailer for the toughest operations. The length of the trailer is 5500mm with 1000mm high half pipe/bathtub sides, with 6mm Hardox steel. A 200mm extension can be fitted to increase the side height to 1200mm. From this, a 1500mm silage bin can be fitted to the trailer with a 150mm high side. A width of 2.7 meters brings its total capacity up to 34 cubic meters.

High sides enable easy filling

A 48-tonne hydraulic ram provides the power to push up any load. This incredible-sized ram tips the trailer at a steep tip angle to aid sticky soils coming out of the trailer and avoid sticking to the deck. To achieve the best flow to such a big ram, a ¾-inch hydraulic hose has been fitted. This helps increase the speed of the hoist in both going up and down. When using the trailer on silage, the last two stages aren’t needed, as the product is already flowing out the back door, thanks to the unique tub design.

The front of the trailer starts as a halfpipe shape and holds this shape 80% of the way down the trailer where it tapers into a square body. This allows the product to have an unrestricted flow out of the trailer. This is extremely helpful on sticky clay where clinging to the steel is a considerable inconvenience on day-to-day site jobs. The non-stick design improves efficiency throughout each day requiring fewer ‘clean outs’ and helping keep the full volume of the trailer available. This also means fewer trips and less fuel – a definite consideration in today’s market.

Efficiency and stability

Saddled underneath this impressive bit of kit is a set of individually sprung, 36-tonne, 14-plate leaf springs. These are extremely heavy-duty and have 10 stud, high-speed braked commercial axles. This set-up ensures the largest loads aren’t going to have a negative impact on durability and longevity. The heaviness of the springs ensures the trailer is reassuringly stable on hillsides on silage carting duties, as they are made to handle over 10 tonnes more than the amount of silage it can hold. A sprung drawbar combined with large 710/50R26.5 tyres ensures a smooth ride on the tractor (and for the operator).

Trailer versatility

Adding and removing the silage sides is made simple by the bin coming off completely. A couple of locking bolts hold the bin down while locating sections slot into the body of the trailer. The ease of changeover means you can be carting rock one minute and an hour later, be set up to cart silage. This capability of allowing the same machine to change between jobs quickly and easily is a huge asset in terms of overall efficiency.

Heavy duty 14 plate sprung axles

Hydraulic hoses on each side with quick couplers allow the hydraulic tailgates to be plugged in quickly and easily. Hydraulic up and over tailgates are standard on the premium plus trailer. Full LED road and marker lights ensure it’s well lit up at night. These come as standard with the unit. Rear lights are well protected by a galvanised steel plate, while reflective strips around the trailer give it a distinct tidy look.

A hydraulic jack stand along with central greasing is also standard – a feature sure to impress the machinery junkies. One feature that cannot be missed is the pristine quality paint work the SlurryKat gear comes with. A premium two-pack paint is applied, featuring a special high-gloss coating, which will hold its shine for several years.
Other optional extras include auto greasing and air brakes.

Test time

Hitched to a CaseIH Puma 240 CVX, my first impressions on the road were around how well it towed, not only in terms of smoothness but also how easy it was to get up to speed and pull up hills (which surprised me, given the amount of formed steel in the build).

Once in the paddock, the SlurryKat really demonstrates its elegance. With large tyres ensuring minimal soil disruption, even while loaded, travelling is straightforward. Pulling over undulating terrain can prove difficult with some trailers, but once again, the large tyre circumference proves its worth. In terms of visibility, unique cut-outs on the right side of the trailer allow the harvester operator to see into the trailer, helping place product with more accuracy.

Central greasing block

A galvanised bolt high on the left side further enhances the ease of filling. The well-designed sloping front takes away the need for a hydraulic drop front and provides an easy target for opening up maize crops while giving extra capacity. I ran the trailer on the pick-up hitch hook. This brings the trailer closer to the tractor than typical, and even in dips while turning, the front of the trailer did not come close to hitting the cab. The 34-cube bin held a whopping 14 tonnes of maize, which gave the springs something to absorb.

The stability of the trailer was also comfortable, thanks to those 36-tonne springs. The manoeuvrability of the SDT was surprisingly impressive and there’s no need for a steering axle. The geometry of the axles to the drawbar is all perfect, providing a great amount of tractor drawbar weight while being easy to manoeuvre.

1.2 metre-high sides carry a big load

This was further heightened while reversing up the stacks and down races, as it was easy to keep on the straight and narrow (and I’m getting out of practice). The 48-tonne tipping ram is a sight on its own as it uncovered itself while tipping. The last two stages weren’t needed at all, as the non-stick design allow rapid exit of the maize. Those extra stages are helpful for carting clay to get a much higher tip angle. A feature to note is the way the hydraulic tailgate latches shut. Most trailers latch vertically, but the SlurryKat latches horizontally, meaning riding up is completely out of the equation. Both silage and dirt tailgates use this latching system, proving to be a tidy and effective design.

The SlurryKat SDT was well suited to the size of the Puma 240, which had a good amount of pull and weight to keep the trailer performing at its peak. The 25-tonne SDT would be well suited to the 180 to 320hp range of tractors depending on the terrain.


There are not many other words to describe the paintwork on the SlurryKat than beautiful. The high-gloss coating makes cleaning after jobs easy. The brush glides down the trailer removing all the maize starch, which generally stains like grease on a white towel.

Build quality is paramount with strength in all the right places. The single-formed 6mm Hardox tub has large supports at the sides and front. The hoses are routed nicely through tubing and tucked out of the way. The only place for improvement would be a rounded edge where the hoses come out of the box section and go to the tractor, as the square edge could damage the hoses.

The 48-tonne tipping ram has no issues with any load

Galvanised trims on the trailer complement its look and design greatly and provide a functional accessory to keep the trailer looking great for a longer amount of time.


It’s hard to fault the SlurryKat SDT as it performed well in all areas of operation, from versatility and ease of use, all the way to the small but crucial features such as the hydraulic jack stand and high quality of build and finish. It’s a unit made to stand the test of time. The ability to rapidly change to and from the silage bin without pulling it to pieces is a big positive. The 6mm Hardox floor and sides further improve the longevity of the investment. The 36-tonne axles under the trailer are made to handle the toughest situations and provide smooth stable transport while the non-stick floor design improves overall daily efficiency. A trailer that can cart dirt, rock, silage, and maize and perform exceptionally at both is a huge advantage to any business.

Having a purpose-designed trailer for New Zealand conditions, and one which is versatile enough to use year-round on a variety of tasks is a clever move by both Brownrigg and SlurryKat. Well-designed and performing trailers like this are worth their literal weight in gold these days, with increasing demands around machinery that’s robust, performs well and is versatile enough to use across several different work requirements.

SlurryKat SDT 25 Specifications

Gross weight 25T
Width 2.8m (at the wheels) 2.7m bin
Length 5.5m
Height dirt sides 1000mm (extension available to 1200)
Height silage sides 1500mm bin, 2000mm to the floor
Cubic capacity silage 18 cube (with dirt extensions)
Cubic capacity silage 34 cube
Tyres 710/50R26.5
Lights Full LED
Drawbar suspension Sprung – 2 coil springs
Axle rating 36T


  • Hardox body
  • Smooth towing
  • Horizontal locking door
  • Quality of finishing and paintwork
  • 48-tonne tipping ram
  • High tip angle
  • 36T 14-plate suspension
  • Easy to add/remove silage bin
  • Very manoeuvrable


  • Plate, where the pipes come out, could rub the hoses

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