Boris Karloff became ill with pneumonia while shooting this project in the freezing rain. It was his last British feature, begun January 22 1968. Karloff had just finished Targets (1968) and would recover enough to shoot four Mexican features in May 1968, his final screen work.
After the firemen turn on the water valves on the fire engine they take the ladder on wheels to the house. However when they cross over the hose pipes you can see that they lie flat on the ground so clearly no water is running through them.