Contact Details

Railko Limited

Loudwater
High Wycombe
Buckinghamshire
HP10 9QU
United Kingdom

Tel: +44 1628 524901
Fax: +44 1628 810761

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Railko Ltd

Railko Limited is a leading developer and manufacturer of engineered high performance plastics and specialises in bearings. Railko bearing materials are non-metallic, non-corrodible and have been specially designed to cope with extremes of operating conditions: loads, speeds, temperature fluctuations, dirty conditions, etc. Depending on the application and grade, these thermosetting resin laminates can operate dry, partially lubricated, or fully lubricated in oil or seawater.

Railkos marine bearings offer significant advantages in terms of reduced vessel through-life operating costs: reduced maintenance, improved reliability and 'kindness' to shafts. They are applied as propeller shaft bearings, rudder bearings, steering gear and deck machinery bushes.


OIL LUBRICATED PROPELLER SHAFT BEARINGS

Railkos latest material development is SternsafeTM. Together with the well- proven CY160LS grade, these materials have been designed for oil lubricated tailshaft bearings and are applied to all sizes of merchant ships and cruise liners. SternsafeTM and CY160LS have proven not to seize or damage the shaft in the event of oil loss due to worn or wire-damaged seals. The benefit to the Owner/Operator is that the vessel can be converted to water lubrication at sea and get to its destination at normal speed.

  • There are no towing charges
  • There is no need for machining down or replacing the shaft (assuming the wire has not done irreparable damage to the shaft)
  • There is no need to run to the cost of keeping a spare shaft in stores and the additional cost of freighting it to the repair yard
  • There need be no knee-jerk reaction to get the vessel into the nearest drydock 'this can be planned' again resulting in minimal disruption to the chartering programme and enabling the most cost effective dry-docking location to be selected.

WATER LUBRICATED PROPELLER SHAFT BEARINGS

Railko NF material was developed for water lubricated (and dry) bearings applications - it is used by over 30 Navies around the World for water lubricated bracket and stern tube bearings in surface vessels and submarines. Railko NF bearings are also used on ferries and supply ships.

To summarise the benefits of using Railko NF material/design as water lubricated propeller shaft bearings; it is used because of its:

  • Low wear rate
  • Extremely low/nil noise signature
  • Ability to run hydrodynamically at very low RPMs - with low/no stick-slip
  • Higher thermal capability than rubber or elastomeric materials
  • Proven shock resistance
  • Higher load carrying capacity than rubber or elastomers 'therefore shorter bearing lengths are possible, leading to'..
  • Weight savings
  • Low thermal expansion - better stability (less reduction of running clearance) if there is a reduction of seawater (cooling) flow, causing over-heating of the system
  • Low swell characteristic
  • Creep resistance - does not allow the shaft to sink-in to the bearing (squeezing the water out from the bearing/shaft interface), leading to a dry (usually noisy) start
  • kindness to shafts - does not tend to allow abrasive particles to embed in its surface (like rubber and elastomeric materials can), therefore causes less scoring of the shaft

RUDDER BEARINGS

Rudder, rudder head carrier and steering gear bearings are subject to some of the most arduous operating conditions. Railko have developed RG22 to meet the latest specifications set by the Classification Societies. Containing 'built-in' lubricants, the product meets the stringent requirements of pressure capability (RG22 is approved for pressures up to 10 N/mm2), low friction (very low stick-slip) and low swell in water. It also has approvals for totally dry operation for upper pintle bearings.

In addition to the SternsafeTM, CY160LS, NF and RG22 materials mentioned previously, Railko supply other materials from their range; be-it the general purpose JL material or the more specialised high temperature material RG15. With zero, or negligible lubrication requirements, tolerance to abrasive conditions and non-corrodibility, applications such as deck machinery bushes, pipe-work and tank expansion pads, seawater lift pump bearings, stabiliser bushes and many applications in submarines can all be serviced from the comprehensive range of Railko products.