Introduction
For the design of the engines of Leeghwater, Lynden and Cruquius, the government committee for draining the Haarlemmermeer engaged the services of the London consulting engineers, Joseph Gibbs and Arthur Dean. Two of the commissioners, Antoine Lipkens and Gerrit Simons, had an engineering background and they played an active role. Contact was soon established with Harvey & C° of Hayle, the largest manufacturer of engines in Cornwall. The buildings were designed by Jan Anne Beijerinck. It is now impossible to distinguish the contributions of each of these men to the final design. Eventually, Harvey made the Leeghwater and Cruquius engines. Fox of Falmouth made the Lynden engine plus the pumps for all three. Van Vlissingen & Dudok van Heel of Amsterdam made all the beams and the boilers.
Design and construction
The Cornish mine-pumping engine is characterized by a beam, or bob, pivoted on a massive wall, with the vertical steam cylinder under one end of the beam and the pump rod suspended from the other. For the Haarlemmermeer engines, a number of pumps (eleven for Leeghwater, eight for the other two) were to be operated in parallel by a single engine, and so the building was made circular, forming the characteristic castellated tower with radially protruding beams.
The engine has two cylinders. The central one, with a single piston rod, is built inside an annular one, with a piston with four rods. All five piston rods are connected to a single crosshead, to which the beam ends are linked by rods. The crosshead and pistons are hollow to contain about 25 tons of variable weight. Together with the piston rods, they form the ballast essential to a Cornish engine. For Cruquius the total indoor weight surplus amounted to about 85 tons.
There’s a list of principal engine data in the Main Engine Status Report.
How Cruquius works
The actual pumping is performed by eight pumps arranged around the circular engine building. The pumps are of the plain bucket type with 73″ barrels. The bucket and foot valves each consist of two semicircular wrought iron clacks in a cast iron frame. The open-top pumps lift the water from the polder level to the drainage canal which encircles the polder, 15 – 17 ft higher. They discharge onto the oak floor of the `collar launder´ running around the building. Both ends of this launder discharge into the canal via automatic sluice gates.
The pump buckets are suspended by chains from the ends of the beams. The beam trunnion bearings rest on the massive circular wall of the main building which is nearly 7 ft thick at the base.
When the crosshead moves up, all pump buckets descend due to their own weight, and their clacks open. When the crosshead descends, the weight pulls the pump buckets up. The bucket valves close, the bucket lifts the water, and the foot valves open to fill the pump barrels for the next stroke.
Boilers
Cruquius originally had six Cornish boilers working at 45 psi. The fire tube was somewhat unusual. The furnace tube terminated a short distance behind the bridge, and four large smoke tubes in a diamond pattern extended from there to the rear of the boiler. This provided a large heated surface, but the connection of the smoke tubes to the furnace tube caused so much trouble that after a few years, a regular single fire tube was fitted.
In 1860 four similar boilers were added. In 1888 the ten old boilers were replaced by six two-fire Lancashire boilers, working at 68 psi. To reduce the effect of the steam surge at the start of each stroke, a large (54″ diameter) buffer vessel was placed across all boilers. This was over 74 ft long.