A waterway barrier, or boom, typically consists of a series of pontoons and buoys used to delineate the dangerous water areas around a hydro facility, or to protect said facility from debris accumulation and ice related blockages.
Over the past 14 years, Geniglace has completed a wide range of seasonal and permanent boom systems across North America which have been designed to protect intake channels and enhance public safety around hydro facilities. This article focuses on Geniglace’s 600mm synthetic ice resistant rotomolded boom.
Booms function by utilising their positive net buoyancy to create a floating barrier which can be used for a variety of purposes. The pontoon connects differently depending on the required use, i.e., whether the system is used for public safety or debris and ice management, but they function similarly regardless. Geniglace’s 600mm ice resistant synthetic pontoon can be used across North America, however, in heavy ice areas a co-extrusion-based HDPE or steel boom would be recommended for their increased durability and load capacities.
Different connection methods are used when a pontoon is being designed for public safety versus debris management and ice control.
For public safety, the pontoons are connected end-to-end in series, and the tension of the system goes directly through the internal steel members on the interior. The connections between the pontoons are heavy-duty shackles and chain sections. Distancing between pontoons follows the Canadian Dam Association’s guidelines and owner requirements.
Connecting the pontoons in this method helps to deter boater access between the pontoons gaps and is more economical than the debris management and ice control connection methods.
The pontoons are connected individually to a central steel wire cable via cable clamps, chains and shackles. The steel wire cable then becomes the primary tension member while the pontoons float individually off the cable.
For debris booms, this connection method allows the debris to be caught on the lower hanging chains and cables. It also allows the hanging of debris screens for finer debris accumulation, where the debris screen is stopped from moving backward in heavy water currents by the chains behind it (as shown in Figure 3).
For ice booms, a boom where the pontoons are connected to an underwater cable are free to move under an ice cover during high loads to alleviate tension on the system. Whereas with end-to-end connected booms, the chain, shackle or designated fuse link would need to fail first for the boom to alleviate loads as it cannot move under the ice.
Case studies
Geniglace’s ice resistant synthetic boom was used as a public safety boom at Christie Lake Dam, near Ancaster, Ontario in Canada. The boom was installed in front of the intakes of the dam and is anchored into the shoreline using drilled anchors. At 162m long, it consists of 36 pontoons which are each 3m in length with 1.5m gaps in between the pontoons.
The boom was installed in 2022 and has performed well since. There have been no component failures, and the exterior shell has held up well to sun fade.
The product was also used as a debris management and ice control boom at Island Lake Dam, near Orangeville, Ontario. The 47m long boom was installed during 2023 in front of the weir and intake structures and is anchored into the shoreline using drilled anchors. It consists of 13 pontoons, each 3m long with 0.3m gaps between them and has also performed well.
The authors are Razek Abdelnour, President, Geniglace; Elie Abdelnour, Senior Project Engineer, Vice President, Geniglace; Matthew Kilmer, Design Engineer, Geniglace; and Oluchi Eze, Project Manager, Geniglace.
Pontoon specifications
Technical specifications of Geniglace’s 600mm synthetic ice resistant rotomolded boom (referred to as a pontoon):
- Dimensions:
- Diameter: 600mm,Length: 3000mm,Weight: 230kg,Buoyancy: 730kg, a positive freeboard of approximately 380 mm,
- Tension resistance capacity: 800 kN,
- Materials:
- Rotomolded Linear Low-Density Polyethylene (LLDPE), used for its excellent low temperature impact properties,Minimum 95% foam filled,Rounded ends for reduced water turbulency,
- Internal WT-Shape for structural rigidity and external galvanized plates for connections bolted together through the shell
- Profile:
- Standard safety yellow for high visibility,UV protection additives used within the LLDPE resin to reduce fading from sun exposure over time,
- Recyclable materials used for environmental purposes when the product reaches end of life,
- Modifications available:
- End-to-end connections (safety booms),
- Wire cable with steel debris screen (debris and ice booms),
