5 Site Survey Mistakes That Stop Spider Lifts Working

Tracked access platforms are versatile, but they require specific conditions to operate safely. Hire projects can stall on day one because of minor oversights during the initial site survey.

A failed hire is expensive: you still pay for transport, machine hire, and your crew is left standing around. Here are five common site survey mistakes in the field, and how to avoid them.

Mistake 1: Confusing Travel Slope with Setup Slope

Many spider lifts can climb steep inclines of up to 30% (around 16.7 degrees) on rubber tracks. However, they cannot deploy outriggers and work on that same slope.

Outriggers have maximum levelling capacities, usually between 10 and 15 degrees. If ground slope exceeds this, the machine cannot level itself. Measure slope *exactly* at the setup point, not just along the travel path.

Mistake 2: Forgetting Outrigger Footprints

People often measure stowed width of a spider lift to check if it fits through a gate, but forget to check if there is enough space to set up. When outriggers deploy, they create a footprint often 3m x 3m or larger.

If setting up in narrow alleyways or between walls, check outrigger setup dimensions. Narrow setup options are available on select models, but usually restrict outreach on the narrow side.

Mistake 3: Overlooking Tail Swing and Boom Clearances

Looking only at the target work area while ignoring what happens during rotation leads to collisions. As the turret rotates, the rear of the machine sweeps out, which can hit adjacent walls or structures.

Check for overhead trees, cables, or building eaves that the boom might collide with as it telescopes upwards.

Mistake 4: Assuming Floor Loadings without Verification

Spider lifts are frequently hired for indoor work in shopping centres or historic buildings. However, machine weights still range between 2.5 and 5 tonnes.

Verify floor loading capacity (in kN/m² or kg/m²) with a structural engineer or site manager, and compare this against outrigger point loads. Spreader plates are nearly always required on suspended floors.

Mistake 5: Failing to Check the Access Route Surface

Driving across soft grass or mud can churn up lawns, break block paving, or cause tracks to sink.

• On turf/soft soil: Use ground protection mats to distribute weight.
• On block paving/curbs: Use rubber track guards or wooden ramps to avoid cracking edges.