Despite Manchester's large number of gasholders, it took a trip to Birmingham for my first climb to the top of one of those remarkable structures. Originally built to store gas in urban areas, they are now mostly decomissioned, with few still used for balancing out fluctuations in the network's pressure.
Pressure in the tanks is achieved through the weight of the top plate, which can move up and down depending on the required storage volume.
We had a number of locations on our list for the evening, but the holders entertained us until the sun rose. What a great night