Manecraft Seals

Kemp Propulsion Systems supply Manecraft Seals (previously John Crane Seals and Deep Sea Seals) by Wärtsilä, which are ideal for small vessels and Yacht seals with a 1” to 2 ¾” shaft. These seals are locally stocked for immediate supply all over Australia, New Zealand and the Pacific Islands. If you are interested in purchasing these seals, click the “Online Store” button below.

Manecraft Seals supplied by Wärtsilä

Manecraft Seals

The Manecraft seal comprises two main components: the stationary seat assembly and the rotating seal assembly, both moulded from tough, oil resistant chloroprene.

The stationary seat has a solid bronze ring bonded into it and is clamped onto the sterntube with two stainless clips, this part remains stationary.

Incorporated into the stationary seat is a red emergency sealing clip. This safety feature is for emergency only and is protected by a tamper proof tag. Under no circumstances should the shaft be rotated whilst this clip is tight. 

The rotating seal assembly is clamped onto the shaft whilst being compressed against the seat. As the shaft rotates, so does the seal assembly.

The sealing face rotates against the stationary bronze seat, lubricated and cooled by the water inside the seal, and a water flush.

An air vent is incorporated in the flush system (see fitting instructions). The bearing spacing must be determined from the thrust bearing to the ‘P’ bracket bearing. Please refer to the bearing spacing section for further information.

Manecraft seals are easy to fit and are direct replacements for old style propeller shaft packed glands. They do not require packing, adjusting, or maintaining and cannot wear a groove in the shaft. Following careful installation, all they need is a quick regular inspection in common with sea cocks, hoses, and other hull fittings situated under the water line.

Manecraft Seals - Safety Features
Manecraft Seals - Detailed Diagram of Features
On monitored test vessels, Manecraft seals have completed in excess of 10,000 hours of service, or 100,000 sea miles and are still in perfect condition. On most vessels, age will be the deciding factor rather than service hours when renewal is necessary.

With the low cost involved, replacement of such an essential component every five years is recommended.

Sealing propeller shafts and rudderstocks for the following marine uses; boat building, boat repair, charter fleets, fishing boats, hire craft and owner retrofits.

Self Adjusting
These seals automatically compensate for face wear, and unlike gland packing, do not require any adjustment.

No Shaft Wear
The Manecraft seal rotates with the propeller shaft, and therefore cannot cause wear of the shaft surface.

Maintenance Free
Once fitted, the seal does not require any maintenance, although a regular inspection should be made in common with other hull fittings below the waterline.

Emergency Safety Seal with Tamper Proof Tag
The red tag is designed to prohibit accidental use of the Emergency Safety Seal until required.

Manecraft Fitting

The Manecraft seal is simple to fit. Most vessels are easily converted to Manecraft and while there are many types of stern gland, they generally fall into three styles.







One of the primary advantages of Manecraft seals is their ease of installation and maintenance. These seals serve as direct replacements for traditional propeller shaft packed glands, eliminating the need for packing adjustments and frequent maintenance. Unlike traditional packing glands that can wear grooves into the shaft over time, Manecraft seals offer a reliable sealing solution without causing damage to the shaft.

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Call our experts on: 08 8312 6555 or email today!