In an introductory stretch tent safety article, we discussed basic health and safety regulations and also listed the parties responsible for heeding these guidelines. Another very important element of stretch tent safety is design and rigging. When followed, the tips and best practices set out below will ensure a successful event.
The sturdiness of a stretch tent’s design is proven either by use over time or by the calculation of a qualified structural engineer. With more complex structures (multiple tents joined together), designs may need to be independently checked by the engineer. As a minimum requirement, such calculations will typically include the maximum wind loading for which the structure is approved and the maximum imposed load permissible. These safety requirements apply to all stretch tent sizes.
Common stretch tent rigging mistakes
As a supplier to the international stretch tent market, our team of experts have years of safety experience – a critical component of the RHI service offering. Industry newcomers often tend to make the same rigging mistakes, so we make it a priority to visit our clients as often as possible and advise on their rig’s safety.
The main focus of such an assessment is rigging techniques. When a physical site inspection is not possible, our clients are encouraged to send us pictures of their setup to ensure it is structurally safe and aesthetically correct.
Stretch tent rigging mistakes include:
- Incorrect pegging and anchoring techniques
- Incorrect pole positioning and angling
- Insufficient safety straps
Pegging and anchoring techniques
- The pull-out force that an anchorage stake can withstand depends on the type of soil, water penetration, and inclination and depth of the anchor.
- Loose soil provides the least resistance and may require special anchors. In this situation, pull-out tests are required to verify the anchor’s resistance.
- Where ground penetration is not possible, heavy ballast weights can be used to withstand uplift forces. The ballast weight requirement is often underestimated and can be several tons per anchor point, depending on the size of the structure.
- Anchors should always be used in accordance with the manufacturer’s manual and be sufficient to resist the maximum uplift force expected.
- Purpose-designed stakes with defined heads, used in conjunction with gang plates, are generally preferred since they do not need to project significantly above the surface. This provides superior anchorage as well as reducing the risk of tripping.
Pegs lifting out the surface
- Site inspections should be thorough and include an assessment of the grounds prior to the event .
- Riggers should ensure that they use the correct length pegs for the type of ground the tent is being erected on.
- The pegs should be at least 25mmx1000mm in size, and 1 500mm if pegging into soft sand. If pegs are too easy to slam in then double or triple pegging should be considered.
- Pegs should be hit in straight (no angle) and the full length of the peg should penetrate the ground.
- All pegs should have covers with suitable padding so not to cause injury if tripped over.
- Every corner- and side-upright pole should be anchored. An absolute minimum for a side-upright pole is one stake that is at least 1 000mm long and 25mm in diameter, driven fully into the ground. Up to date requirements for the number of pegs required at every point depends on the size of the tent. This information can be requested from RHI.
- Intermediate points on the stretch tent must also be anchored, even if uplift forces are countered at the main anchor points, as lateral movement can destabilise the structure and cause injury.
- All side-upright poles should have the means to spread the load at the base to prevent sinking when erected on soft ground.
- Stakes and ropes near exits or other walking routes should be fenced off or clearly marked to prevent people from walking into or tripping over them. The responsibility of erecting fencing and indicating designated walking routes and will normally lie with the event organiser, but the stretch tent contractor should ensure that the organiser is aware of these safety issues.
Insufficient tension in the tent
- Riggers should ensure that pegs used at floating sides / entrances are the correct distance from the tent in order to achieve the desired lateral stretch in the body of the tent, as far too often the pegs are too close to the edge.
- The correct distance to peg is the same distance as the height of the pole being used at that point.
Pole positioning and angling
Central poles falling over
- A good test of pole length is if three strong men can lift a central pole off the ground, then it should be replaced with a longer pole, or moved to where it can’t be lifted.
- If extreme weather is predicted, ensure appropriate base plates are used.
- Local weather patterns and direction of prevailing winds should be considered when planning open sides and entrances, as gusting winds can cause the fabric to lift off the poles.
- Central poles should be placed upright, no less than 4.5m and no more than 6m apart or away from another central pole or edge of the tent.
- Correct pole lengths will create the ideal run-off with no flat areas. When more than one row of central poles is needed, ensure the lengths are staggered with the longest poles placed in the centre of the tent.
Insufficient tension in the tent
- Side poles that are positioned too upright will prevent ideal lateral tensioning in the body of the tent. Side poles should be hit in at a 15° angle once the ropes are tensioned.
- A useful tip is to mark the point on the ground before lifting the edge of the tent, as this is the point where the base of the side pole should be positioned.
Insufficient safety straps
- It is imperative that safety straps are use with medium- to large-sized tents, especially where more than one central pole is being used.
- Safety straps should be placed in the “valley” between each row of central poles. The number of stakes required for the storm bolts over different sized tents do vary. Please consult RHI for more information.
- Where the tents join where linked together is an excellent opportunity to use a safety strap by passing the strap through the carabineers that link the tents together.
Other articles on stretch tent safety:
- Stretch tent safety 101
- Client awareness
If you would like more information about RHI stretch tents, get in touch with us.