What makes the Castoldi waterjet drives different from all the other ones on the market ? Exclusive features and benefits.

Castoldi waterjet drives are equipped with exclusive features making them an unique, self contained propulsion system.

Among these, the most important ones are:

The integrated gear box/hydraulic clutch:

The light-weight built-in gear box comes with integrated hydraulic clutch in most of the Castoldi range. The wide range of transmission ratios options (from N. 17 to 26 according to the model) is the ultimate solution for engine coupling system allowing many advantages at once:

» A very fine r.p.m. matching for every selected engine. This means full power absorption without over loading the engine regardless of the boat speed. With correct use the engine benefits from a longer life than with conventional propellers.

» The use of the integrated gearbox, allows the use of a single stainless steel impeller designed without the constraints to directly match the engine, as the matching of engine delivery curve, versus power absorption is done through the gears, and not through the use of many different type of impellers.

» This single axial flow impeller system with built in gearbox can easily meet a high number of engine matches.

» Allows high jet input shaft, almost at the same level of the engine shaft. Allows a cardan shaft to work in a more favourable condition and enables the design of the impeller shaft and whole water jet unit tail almost horizontal, resulting in better thrust delivery.

» It minimises bad boat trim problems, by having the thrust delivered parallel to the keel line instead at an upwards angle.

» Built in gearbox and integrated hydraulic clutch drastically reduces the engine room/installation length.

» The lower impeller shaft , produces a lower centre of thrust , giving better directional stability.

» The integrated gearbox allows for the installation of Castold’s “ClearDuct” system on some present and future models.

» It reduces machinery weight and cost, not having to purchase a marine gearbox.

The Axial flow impeller:

Castoldi impeller design is of the true axial flow type.

The axial flow “pump” operates on a high volume flow rate and low pressure. Thanks to the high flow used to produce thrust, instead of a low flow, high pressure type pump, the following advantages become evident.

Loss of performance and impeller changes and rebuilds from tip wear are at a far greater interval than waterjets that rely on tight impeller tolerances for engine power absorption , and the low flow high pressure jet stream delivery.

Cavitation resistance over the hull power and boat speed operation range is increased thanks to its high volume design ,and increased blades tip clearance sensitivity.

Fewer impeller and stator blades allows and easier discharge of ingested debris.

The disconnecting multi-disc hydraulic clutch (H.C. Series):

This light-weight and most useful facility enable the complete disconnection of water jet from main power source, whilst the engine is idling.

specially useful in engine warm-up and controls’ checks, it can be invaluable in operational circumstances for performing several daily boat stops while maintaining the boat perfectly standstill and without ingesting debris or sand of mooring in dirty or shallow waters and without jet turbulence, yet with full engine power running and manoeuvrability instantly at hand.

In conjunction with the movable inlet protection grill, it allows the quickest and most efficient cleaning operation of the jet intake.

It is operated by an electric control through on-off switches.

The lubrication:

All bearings are of the rolling type and lubricated by the same oil lubricating the gear wheels sets. They never come into contact with sea water and can last for many thousands of hours.

The input shaft and the impeller shaft:

The shafts rotates inside the jets oil chamber and are perfectly protected if any debris should enter the duct. The shafts rotate on standard oil lubricated roller bearings avoiding vulnerable water lubricated impeller support bearings.

The main water inlet:

The improved Castoldi water intake is positioned very close to the transom. This avoids aeration in rough conditions fast operations and increases performances by recovering the boundary layer stream.

The flush mounted movable grid :

The inlet grid protects the water intake from suction of floating debris and performs self-cleaning operations through the opening of the two sets of bars, electro/hydraulically controlled, from the wheel house by the helmsman.

The flush mounted grid’s bars have smooth hydrodynamic profile able to control the water flow with minimal losses. This is absolutely the most efficacious anti-clogging system as it prevents debris to enter into the jet duct driving it away with a simple and quick operation. This system together with the “Clear Duct water flow reversing system” available on some models at present, is the most effective and economical method of clearing the grill and duct available.

These exclusive features grant to Castoldi Waterjet Drives unique benefits..