Allen Gearbox - Maintenance agreements
Tilbury Power Station, UK
Project background
Opened in 1968, Tilbury ‘B’ power station is operated by RWE Innogy in Tilbury Essex. It is a 1400 MW coal-fired power station which feeds into the national grid, meeting the needs of approximately 1.4 million people. It is located on the River Thames in Essex and the generation process is cooled by re-circulating the River Thames water.
For each of four main 500 MW turbines, there is:
- 1 x motor driven boiler feed pump – this is to control the amount of water being fed to the main boiler
- 2 x start / stand-by pumps – to aid the start and run down of the main turbines
- 1 x circulating water pump – to provide critical cooling water.
Each unit has an Allen epicyclic gearbox as follows:
| Boiler feed pumps |
– 680 HP |
4750/3082rpm |
| Start / stand-by pumps |
– 6,400 HP |
1490/4907rpm |
| Circulating water pump |
– 2950 HP |
165.5/993rpm |
Therefore Allen Gears have a total of 16 gearboxes plus 2 spares, installed in the plant. 4 boiler feed pump gearboxes, 8 start/stand-by pump gearboxes and 4 circulating water pump gearboxes.
The challenge
These units were installed in the 1960’s and were overlooked for many years, suffering under-maintenance and neglect.
The customer was looking for a simple maintenance solution - where it was re-assured that the units would run without problems in the future, with guaranteed maintenance costs.

The solution
Allen Gears have set-up a 6 year maintenance contract which includes a fixed price contract for two years.
Allen Gears will return all the boiler feed pump gearboxes and start stand-by units to Allen Gears at intervals agreed with the customer.
AG will – go to site and remove units and send to AG factory
- At AG site we will carry out a full internal inspection
- Including strip, inspection, report and recommendations
Each unit will be inspected every 12 months.
The contract also guarantees fixed prices for all major parts which may be recommended following the inspection.
Technical Data
| Requirement: |
Full on-going predictive maintenance of critical gearboxes |
| Plant: |
Tilbury Power Station |
| Operator: |
RWE Innogy |
| Application: |
Boiler feed pumps and start stand-by pumps |
| Gearbox Type: |
Allen Gears epicyclic gearboxes |
|