TS-LV Snow Rake
Area of Application
Flexible-net snow rakes are static defense structures installed on steep slopes to prevent the initiation of avalanches. They are most often used for protecting urbanized areas and linear infrastructure such as roads, pipelines and other utility corridors that pass through mountainous terrain. Snow rakes are similar to larger snow nets but are more effective for snow depths up to 2.5 m.
Simple Installation
The net of the snow rake is installed on the upslope side of the fence but is in the same vertical plane of the post. This greatly simplifies installation. Upslope retention of the post head is provided by a single steel wire rope that is installed in the fall line to reduce the effects of drag.
Base Plate
The base plate is similar to that used for standard hinged rockfall catchment fences. It uses a tension anchor on the upslope side and a compression anchor on the downslope side. The lower bearing rope is led through a guide that secures its position while at the same time allowing deflection.
Post Head
The upper bearing rope is fixed to the post head using U-bolts. A deflection guide is provided to protect the bearing rope while it experiences large deflections during fully loaded conditions.
Adaptable to Topography
Due to the highly flexible nature of the Omega-Net, snow rakes and snow nets by Trumer are highly adaptable to difficult terrain. They can be installed at sites that would be impossible using more rigid materials.
Classification
| Model | TS-LV Snow Rake |
| Style | Hinged |
| Design Pressure [kN/m2(lbf/ft2)] | up to 150 (3133) |
| Available Heights [m (ft)] | up to 2.5 (8.2) |
| Verification | Analytical (site-to-site) |
Primary Net
| Model | Omega-Net 4.5/100 | Omega-Net 6.0/135 |
| Type | Steel Wire Cable | Steel Wire Cable |
| Rope Diameter [mm (inch)] | 4.5 (0.18) | 6.0 (0.24) |
| Rope Construction | 1 x 7 Spiral | 1 x 7 Spiral |
| Single Wire Diameter [mm (inch)] | 1.5 (0.06) | 2.0 (0.08) |
| Corrosion Protection | Zn | Zn/ZnAl (Class A) |
| Mesh Size [mm (inch)] | 100 x 100 (3.9 x 3.9) | 135 x 135 (5.3 x 5.3) |
| Unit Weight [kg/m2(lb/ft2)] | 2.7 (0.55) | 3.6 (0.74) |
| Mesh Tensile Strength calculated [kN/m (lbf/ft)] | 154 (10,552) | 246 (16,856) |
| Connection to Main Ropes | Threaded | Threaded |
| Connection to Adjacent Panel | 1/4" Shackle | 5/16" Shackle |
Omega-Net
The primary net material used in Trumer systems is called the Omega-Net. It is a steel cable net made from spiral rope that has thick individual wires to resist abrasion. The strands of rope are pre-bent into arcs resembling an omega shape and then woven together to make the net. This process yields an extremely strong net with high flexibility and energy absorption characteristics.
Bearing Ropes
| Quantity per fence segment | 2 |
| Max. Rope Diameter [mm (inch)] | 24 (0.945) |
| Corrosion Protection | Zn or ZnAl (Class A or B) |
| Brake Element per rope | n/a |
| Brake Element Type | n/a |
Middle Ropes
| Quantity per fence segment | 1 |
| Max. Rope Diameter [mm (inch)] | 24 (0.945) |
| Corrosion Protection | Zn or ZnAl (Class A or B) |
| Brake Element per rope | n/a |
| Brake Element Type | n/a |
Retaining Ropes
| Quantity per post | 1 |
| Max. Rope Diameter [mm (inch)] | 24 (0.945) |
| Corrosion Protection | Zn or ZnAl (Class A or B) |
| Brake Element per rope | n/a |
| Brake Element Type | n/a |
Support Structure
| Post Type | HEA/HEB |
| Post-Base Connection | Hinged |
| Integrated Ladder | Rungs every 0.5 m (19") |
| Rope Guides | Integrated |
| Base Plate Connection | Tongue and pin |
| Anchors per base plate | 2 |
Post Base Support
Retaining Rope Anchorage
Lateral Anchorage
Typical Cross Section
Internal Stabilization
Typical Layout (Front View)
NOTE: Every avalanche structure is custom designed for a specific site and loading conditions and so the exact details of the system will very from site to site. This is an important aspect of avalanche mitigation since standardized (e.g. CE marked systems) cannot address site specific requirements.