Innovations
Water Bag
The water bag system for controlling water-filled rubber dams is a Floecksmühle design and development. The water bag is an open control system ensuring easy and safe operation of the dam.
Using the water bag system may reduce the space requirement of the control system considerably, as the water bags of all spans are located in a single shaft. Therefore the water bag is very low-maintenance system.
Safety systems
Depending on the construction design and materials used, as well as on the relevant conditions on site the service life expectancy of a bladder is 30 years. Minor damage to the bladder may generally be repaired by cold vulcanization. When carried out properly, the repair of the damaged area is permanently durable.
Using the Floecksmühle safety systems may reduce the probability of damage to the bladder and increase its service life substantially.
The design and use of these safety systems are determined by the relevant application and local site conditions. In a personal meeting we will be pleased to give more detailed information about the specific execution of the dam at the customer’s site as soon as the relevant operational conditions are known.
Generally the following safety systems are available:
FlexFlector ®
When the rubber dam is overtopped, pressure variations tend to occur on the upstream and downstream sides of the dam structure due to changes in the flowing velocity and flowing direction of the overtopping water. In certain operating conditions, this leads to oscillations of the rubber dam body and, as a result, to friction between the membrane and the concrete surface. The oscillation amplitudes can be significantly reduced by installing dampers, thereby increasing the service life of the rubber dam.
In cooperation with BAW (Federal Agency for Water Management), Floecksmühle developed various shapes and sizes of such dampers between 2004 and 2006, known as FlexFlector® (deflectors). In the summer of 2006, FlexFlector® deflectors were tested under real conditions on a rubber dam. The measurements were attended and monitored by the BAW Karlsruhe. The result showed that oscillation amplitudes could be reduced to approx. 30% when using FlexFlector® deflectors.
The good experience from the development and the test show the need to provide FlexFlector® deflectors for reducing oscillation in overtopped rubber dams. Once the bladder is installed on site, the FlexFlector® deflectors are cold bonded to the bladder surface.
Automatic deflation system
In the event of energy failure or malfunction of the control system an automatic safety system ensures deflation of the bladder as soon as the so-called safety retention level is exceeded.
Automatic deflation systems are used on both water-filled and air-filled rubber dams. Their activation is subject to the upstream water level and ensures controlled deflation of the rubber dam if and when the electronic control system does not work properly.
As soon as the upstream safety retention level is exceeded, the system is activated automatically. Depending on the given conditions, existing systems may be adjusted or customized solutions may be designed.
Anti abrasion protection layer
An anti abrasion protection layer protects the fully or partially deflated bladder against abrasion from friction on the surface of the dam structure. At the same time, the protection layer prevents roughening of the dam structure surface resulting from the water jet impact on the downstream side of the rubber dam. There is no need for additional treatment or smoothening of the concrete surface. Due to the elastic nature of the anti abrasion protection layer, it also prevents damage, especially from large bed load.
Modular design
Building on its wide experience gained, Floecksmühle has developed a very easy-to-install design for rubber dam systems. The various components (fixing system, bladder etc.) are preassembled and prepared to the maximum extent possible at our own workshop. This allows for in-depth quality control of all components before delivery to the customer and quick assembly on site.
Detailed assembly drawings and on-site supervisors (from Floecksmühle) have proven the value of this modular design, which also allows for assembly by the customer's own personnel, supervised and trained by experienced Floecksmühle employees.
This efficient and flexible system ensures high installation quality with significant savings in time.
FishFlector ®
Over the past years the significance of ecological aspects has increased notably in the planning of rubber dams, while the issue of fish passes across dams is mostly unstudied as yet.
In this context Floecksmühle has developed what are called FishFlector® deflectors as a prototype for a specific project in Switzerland. The FishFlector® system consists of a continuous row of jet deflectors fixed to the bladder by vulcanisation.
The FishFlector® deflectors channel the water flow directly into the downstream reservoir so migrating fish do not get in contact with the concrete slab. The a sufficient water cushion forming on the downstream side of the rubber dam allows fish to make their way safely across the dam.
