The occupational safety serves to manage and minimise dangers for the health and safety of employees at work. It is thus part of occupational protection in the sense of occupational health and safety law, which requires measures to prevent accidents at work and work-related dangers to health, including measures for human-orientated work planning.

The following measures must be adhered to on the job site

  • Traffic safety
  • Job-site safety and
  • Personal protective equipment


On the rehabilitation vehicle, the flashing lights are to be switched on; it should be placed against the direction of traffic if possible. All employees must wear reflective protective clothing.

The “Caution Construction Works” triangle should be erected in both directions at the appropriate distance to the vehicle (30-50 m from the job site in urban areas, 80-100 m outside urban areas). If there are corresponding traffic laws applicable, the job site must be safeguarded in accordance with the traffic signage plan. The traffic signage plan serves to secure work areas on roads. Applicable guidelines are the guidelines for safeguarding work areas on roads. The plan includes the location and selection of traffic signage and lane markings that are necessary to safeguard the work area.


The job-site safeguarding comprises securing the job site with warning poles, cones, shaft blocking grids and cable and/or pipe bridges.


The employer must determine the properties of personal protective equipment, so that it protects against the dangers that have been established. The personal protective equipment must be provided to each employee by the employer.

The personal protective equipment includes

  • Helmet
  • Protective clothing
  • Safety shoes
  • Protective goggles
  • Breathing protection masks
  • Hearing protection

Protective equipment for sewer rehabilitation also includes

  • Safety belt / safety harness
  • Tripod to protect against falls
  • Gas detector, 3-gas or 5-gas
  • Breathing apparatus/oxygen
  • UV protective goggles
  • Wading trousers


There are particular challenges for occupational protection on an inliner job site. We would like to point out the following decisive aspects:

Opening shaft covers / securing the shaft

Shaft covers come in different shapes and sizes. When opening, care must be taken to ensure that only suitable lifting tools and devices are used, because the use of incorrect devices may lead to injuries.

Also, the shaft must be secured sufficiently with suitable and safe blocking material each time it is exited!

Positioning shut-off bladders

Only shut-off bladders or through-flow bladders that are in good working order can be used. Before positioning and filling the impermeable cushion, the pipe must be checked for damage or impurities. The pressure gauges used to position the shut-off bladders must also be an approved type and in good working order.

Once the shut-off bladder has been fitted, the manhole must be left – there is the danger of personal injury or death! Shut-off bladders or through-flow bladders must be secured from moving out of position. When working in the nominal diameter range of DN 700 – DN 1600 (walk-in sewers), further safety precautions must be made.

Insertion of the glide foil

The glide foil is only to be placed on suitable supports. The supports must be designed in such a way that the load-bearing tube cannot slide out. The insertion speed is to be adapted to the circumstances of the job site. The radio connection must be checked.

Insertion of the liner

It must be ensured that there is a good radio connection whilst the liner is inserted. The liner must be checked as is it let into the manhole. For larger dimensions in particular, suitable installation aids, such as a conveyor belt, installation vehicle, roller conveyor or crane must be used. It is also important to secure the end of the liner well.


The curing parameters of the installation instructions are to be adhered to. The work packers are to be secured against moving out of position. If the liner has been subjected to compressed air, there is a danger to life if the manhole is re-entered and this must be avoided!

Cutting the liner after curing

When cutting the liner, protective clothing, a helmet and gloves must be worn. Due to the respirable dust, a mask with breathing protection with the appropriate filter must be worn. Only suitable cutting tools or machines can be used.