We are specialists in the field of naval power conversion and distribution, with equipment installed on virtually all of the Royal Navy’s submarine and surface fleet.
We have a strong export business and our equipment is deployed on many foreign Navies, including Australia, Malaysia, Oman, Spain, Turkey and Japan.
Our latest designs support a number of current European warship programmes including the Type 26 destroyer, the QE Class Aircraft Carriers, the S-80 submarines being built in Spain and DCN’s Scorpene Class submarines.
In the normal course of events electrical supply is 115V AC or 440V 3phase generated internally and distributed throughout the vessel. This will support basic functions such as entertainment and domestic lighting through to Command and Control and weapons systems. A recurring theme in our equipment is support of electrical power in emergencies (such as the loss of main ship’s power) and the need to convert that original AC supply either to a higher frequency or to DC. Below are some examples that illustrate the broad range of specifications and applications.
Instant battery support for critical functions if main power is lost. Emergency power cuts in with no interruption and is available typically for up to 30 minutes. We supply equipment up to 60kVA for the Type 45 Destroyers, Type 26 Frigates and QE Class Aircraft Carriers.
Ships supply is 60Hz but up to 400Hz is required for sophisticated electronics like radar, gyros and weapons systems. We provide this conversion with a wide range of equipment up to 40kVA.
DC power is required on board for many applications – machinery, fire doors, emergency communications. We convert ship’s supply to 28V to 24V/28V or 120V DC for these purposes.
Often the rectification of AC to DC is far from being all that is required. Our support theme is reinforced with the need for such systems backed-up by batteries for emergencies. In addition we meet the need to distribute the power once rectified to a variety of facilities. The battery supported rectifier can incorporate what is in effect a mini switchboard for this purpose.
Equipment of this sort can be found on T45 as well as on Spanish Frigates, Australian Destroyers and the new MARS Tankers.
Like commercial aircraft, helicopters need ground assistance to start. This takes the form of 28V DC power up to 1800 amps.
Our Helicopter Starting Rectifiers are in service worldwide from New Zealand and Australia through Spain and Norway to virtually all helicopter carrying vessels in the Royal Navy. As well as the rectifier we supply a 40kVA Frequency Converter together with cabling and a variety of flight deck controls making a complete system for the starting and servicing of modern helicopters.
If emergency power can be essential in supporting critical functions on a surface ship, it clearly has even greater importance on a submarine.
We have designed and supplied a combination of battery packages with associated chargers for submarines that supply emergency power to lighting and communications in the event of a loss of main power.
Currently these are deployed on Scorpene submarines and will shortly go into service in the new Spanish S-80 class.
For surface ships we have designed and supplied an extensive range of battery boxes. These afford a secure means of housing the valve-regulated lead acid batteries, used to back up the ship’s main and other supplies.
In addition to these main systems Gresham manufactures a wide range of individual support equipment including:
Valve Regulated Lead Acid Batteries (VRLA)
Suitable for all standby applications including Telecommunications, UPS, Emergency Lighting. Endurance range Batteries from Yuasa are the engineer’s choice for even the most critical standby applications, available in 15 year models.
Suitable for all standby applications including Telecommunications, UPS, Emergency Lighting. Endurance range Batteries from Yuasa are the engineer’s choice for even the most critical standby applications, available in 12 year models.
The NPL range is an enhanced NP design resulting in a longer service life (7 – 10yrs). All other attributes and operational characteristics are the same, thereby maintaining the benefit of a common mechanical and electrical design for users of both products.
Yuasa NP, NPC and NPH Batteries Utilising the latest advance design Oxygen Recombination Technology, Yuasa have applied their 80 years experience in the lead acid battery field to produce the optimum design of Sealed Lead Acid batteries.
The SWL range is an enhanced NPL design resulting in an improved energy to density ratio, giving up to 40% extra discharge capacity. All other attributes and operational characteristics are the same, thereby maintaining the benefit of a common mechanical and electrical design for users of both products.