Sleipner's SH series are hydraulic tunnel thrusters from the SH100 (80-100 kg) to the SH2200 (up to 2,200 kg), with SRHP hydraulic retracts in between. They suit larger yachts that already run hydraulics and need long, continuous thrust. The thruster is the easy part; the pump, valves, cooling and plumbing are where the cost and design work sit.
What we like
- Huge range, from 185 mm to 730 mm tunnels
- Heavy-duty and light-duty thrust ratings published for each model
- Several hydraulic motor options per size to match your system pressure
- Variable speed and S-Link control listed
- Compact thruster units for their thrust
Watch out for
- Needs a properly designed hydraulic supply
- More plumbing, more potential leak points
- Harder to retrofit on a boat without hydraulics
- Motor choice must match available flow and pressure
Hydraulic thrusters are a different conversation from DC units. With an electric thruster, you pick a model and then work out the battery. With a hydraulic thruster, you work out the hydraulic system first, and the thruster model almost falls out of that. Sleipner's SH series is a good example, because each thruster size comes with a menu of hydraulic motors to suit the system feeding it.
Who should be looking at SH
Mostly owners of larger yachts and workboats. Sleipner's smallest SH100 is listed for boats around 9-16 m, and the range climbs to the SH2200 for vessels around 48-70 m. Sleipner notes the SH2200 BA200 version is approved for DNV-classed vessels.
The strongest case for hydraulic is a boat that already has a hydraulic system for stabilizers, windlasses or other gear, and an owner who needs thrust for long periods: holding position in current, working alongside, or docking big windage in a strong breeze. Electric DC brushed thrusters have short duty cycles. Hydraulic units do not have the same motor heating limit.
If the boat has no hydraulics, compare carefully against brushless electric options like Sleipner's eVision range, which Sleipner now rates for continuous running at full thrust. Our electric vs hydraulic comparison goes deeper.
The range
| Model | Heavy duty / light duty thrust | Tunnel ID | Sleipner vessel size |
|---|---|---|---|
| SH100 | 80 / 100 kg | 185 mm | 9-16 m |
| SH160 | 140 / 160 kg | 215 mm | 11-19 m |
| SH240 | 220 / 240 kg | 250 mm | 13-23 m |
| SH320 | 270 / 320 kg | 300 mm | 13-23 m |
| SH360 | 360 / 360 kg | 300 mm | 18-33 m |
| SH400 | 400 / 400 kg | 300 mm | 18-33 m |
| SH420 | 380-420 / 420 kg | 386 mm | 22-35 m |
| SH550 | 500 / 550 kg | 386 mm | 25-40 m |
| SH700 | 700 / 700 kg | 412 mm | 29-44 m |
| SH1000 | 1,000 / 1,100 kg | 513 mm | 30-45 m |
| SH1400 | 1,400 / 1,400 kg | 610 mm | 40-55 m |
| SH2200 | 1,800-2,200 kg | 730 mm | 48-70 m |
Where Sleipner's figures vary by motor option (SH420, SH2200), the range is shown. Sleipner also lists three hydraulic retracts: the SRHP240 (220/240 kg, 250 mm), SRHP320 (270/320 kg, 300 mm) and SRHP650 (500/650 kg, 386 mm, listed at 300 kg unit weight).
Heavy duty, light duty
Sleipner publishes two thrust figures per model. The lower heavy-duty figure is what you should size against if the thruster will work hard and long. The light-duty figure is the peak for shorter use. On some big models the two are the same.
That distinction matters more on hydraulic boats than on electric ones, because the people who choose hydraulic usually do so precisely because they expect long runs: holding station while waiting for a lock, working a mooring in current, or keeping a big hull off a dock in a blow. If that describes how you will use it, treat the heavy-duty figure as the real rating and size from there. Our sizing calculator gives a starting number for the thrust you need.
Picking the motor
This is the part that trips people up. An SH240, for instance, is listed with U8, U10, U11, U14, U16 and U19 motors. Each needs a different pressure to make the same thrust. With the U11, Sleipner lists 158 bar for 60% thrust, 211 bar for 80% and 264 bar for 100%. With the U19, full thrust comes at 153 bar. On some combinations, such as the SH240 with the U8 motor, Sleipner notes the maximum achievable thrust is limited (76% at 275 bar).
So the motor choice depends on what pressure and flow your pump can deliver at the engine speed you dock at. That is a question for whoever designs the hydraulic system, and it should be answered before the thruster is ordered.
Install considerations
- Hydraulic supply. Pump size, how it is driven, valves and the proportional control valve all need matching to the thruster and to everything else on the circuit.
- Cooling. If you plan long thruster runs, the oil cooler and reservoir have to handle the heat. Continuous thrust is only continuous if the oil stays in range.
- Plumbing. Hoses and fittings into the bow add weight and potential leak points. Route them with access in mind.
- Tunnel. Sleipner publishes tunnel minimums for each model; the SH240 lists a minimum tunnel length of 300 mm and recommends 600 mm.
- Controls. Sleipner lists variable speed control and S-Link compatibility on these units, so they can share control panels and joystick systems with Sleipner's electric thrusters.
The larger SH models use twin counter-rotating propellers, which Sleipner says give the most thrust for a given tunnel diameter. Q-Prop low-noise propellers are listed as compatible.
The weak spots
The thruster itself is compact. An SH240 is listed at 13.5 kg, far lighter than an electric thruster of similar output. But the system around it is not small, and it is not cheap. A hydraulic install is a design job with several trades involved. Service needs someone who understands hydraulics as well as thrusters. And if the hydraulic system is down, so is your thruster.
Alternatives
Vetus hydraulic thrusters are the other common choice in this range, though Vetus's line covers fewer sizes. For boats where hydraulics are not already aboard, Sleipner's own eVision electric thrusters or AC thrusters may be simpler.
Verdict
If your boat already runs hydraulics and you need long-duration thrust, the SH series is about as complete a range as you will find, with published pressure curves that make proper system design possible. If your boat does not have hydraulics, price a brushless electric option alongside it before deciding. Either way, the hydraulic engineer should be in the conversation from day one. Get in touch and we will bring ours.
Questions people ask
What do heavy-duty and light-duty thrust mean?
Sleipner publishes two nominal thrust figures for each hydraulic model. Heavy duty is the lower figure, for heavier, more continuous use; light duty is the higher one. The SH240, for example, is 220 kg heavy duty and 240 kg light duty. Size on the heavy-duty number if you expect long holds.
Why are there so many versions of one SH model?
Each size is offered with different hydraulic motors (such as U8, U11, U14 on the SH240). Each motor needs different pressure for the same thrust. You pick the one that matches the flow and pressure your system can supply. On some combinations Sleipner notes that full thrust cannot be reached at maximum pressure.
Can a hydraulic thruster run continuously?
Hydraulic thrusters avoid the motor heating limits of brushed DC units, which is the main reason people choose them. The real limit becomes the hydraulic system: oil temperature, cooling capacity and how the pump is driven.
Is hydraulic better than electric?
Not automatically. On a boat that already runs hydraulics for stabilizers or other gear, it is often the natural fit. On a boat without hydraulics, a modern brushless DC thruster may cost less to install. See our electric vs hydraulic comparison.
- Sleipner SH240 U11 product page
- Sleipner SH100 U11 product page
- Sleipner SH420 U29 product page
- Sleipner SH1000 BA110 product page
- Sleipner SH2200 BA250 product page
- Sleipner SRHP650 BA45 product page
- Imtra Sleipner hydraulic thrusters
Manufacturers update their lines. Confirm current model numbers with us or the maker before you buy.