Rolling gates, the solution for large locks
In the previous blog (click here to read more) the mitre gate as the ideal solution for small and medium sized locks was discussed. But there are more gate types available for the designer. Just as with weirs, there is a whole range of concepts, some more exotic than others and each useful for a specific situation depending on the conditions: sector gates, radial gates, etc. But unlike weirs, the rolling gate and the lift gate are primarily used as an alternative to the mitre gate for locks. In this article we will discuss the rolling door, which is used for wide locks, such as most large modern sea locks in Panama, the Netherlands, Germany and Belgium.
Table: (some of the) largest locks in the world with rolling gates (source: Wikipedia)
By rolling gate it is meant that the gate moves across the chamber of the lock. A rolling gate is made up of skin plating that can be single or double and that fulfils the water retaining function. The skin plate is strengthened and supported by means of stiffeners, often designed as trusses. There are often air boxes with a filling and draining system installed in the door which increase the stability during rolling when filled and also allow the door to float during maintenance (on the door, trolley, rails or gully).
The door is opened and closed by means of 2 carriages that roll the door in and out of the door chamber on rails in the lock floor, driven by a winch system. In the traditional versions, both trolleys were at the bottom, under water. With the more modern system a wheelbarrow is usually formed: there is one at the bottom and one at the top. The biggest advantage of this is that a car is flooded less, which is more maintenance friendly. In addition, two, albeit shorter, rails are required and the door is more stable when moving. On the other hand, a heavier cantilever arm is attached to the door and there is more space required needed next to the door chamber. A recent example of the wheelbarrow rolling door was discussed in a previous blog post about the Royers lock (click here to read more!)
A further advantage is that a road surface can be provided for light traffic, which can be used, for example, when heavy traffic bridges of the lock complex are temporarily put out of operation (click here to read more in a previous blog post).
There are also other types of rolling doors such as vertical rolling doors that roll up and down and undergo vertical translation (e.g. Bollene Lock, Leerstetten, Germany), but this is generally not an economic type due to the large earthworks or the large superstructure required. Another concept of rolling gates are hanging doors, which hang via cables on wheels that roll on rails above the door chamber. This type of door is also the exception and has been applied in the Lanaye lock.
SBE has extensive experience and knowledge about this type of lock and doors, as the table above indicates. Do you want to know more about these project? Check our portfolio by clicking here!