On the upper level of the museum is the Top Bay, where during the working life of the pumping station all the refuse for incineration was received in the tipping area. Today it is used to house some of the museum's growing collection of engines and heavier exhibits.

On each side of the original three boilers were destructor furnaces, which would be fired by shovelling the refuse through a hole in the floor, into the destructor furnace. This practice of burning Cambridge's refuse carried on for the majority of the pumping stations' working life, until changes in refuse collection meant that refuse was not collected on Sundays. To overcome this problem, a forth boiler was installed in 1923 that used coke as its primary fuel source.

The most striking exhibit is the large mill engine which was built in Cambridge in the mid 19th century at the foundry of JI Headly.

It was supplied to Thomas Evans Leatherworks at Sawston where it drove machinery until 1968. It was dismantled and moved to the museum in 1970 and has now been re-erected and restored to working condition.

Next to the Headly engine is a small, steam driven tar pump, which at one time worked at the Cambridge Gas Works.

The wooden structure that covers the top bay was built in 1939 as a blackout to hide the glare of the furnaces from the bombers flying overhead. I could spend three days or more telling you about all the amazing stuff in here but i think you should come in and see for yourself.