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High rise test Älvsborgs Bridge, Gothenburg, Sweden, March 2, 2016

Participants in the test were Cold Cut Systems and RSG, Räddningstjänsten Storgöteborg.


(You may also have like this: >> Read about our Cobra high rise test together with Rotterdam-Rijnmond Brandweer, NL)

The following areas generated interest:

  1. Spray pattern at high altitude.
  2. Pressure and flow characteristics.
  3. Vertical abrasive movement within the transport hose.
  4. Effects on operation resulting from the accumulation of abrasive when the system is stationary for a time with the hose hanging vertically
  5. Experience in vertical pipe runs at high elevations.

Results and comments:

Test 1: Spray pattern at high altitude

  • Height: 100 meter
  • Pump pressure: 300 bar
  • Hose: 200 meter, ½ ”
  • Nozzle: 2,3 mm
  • Nozzle pressure: 228 bar

Comment: If the hose is empty of water, (in this case it was partially empty), it can take some time for the system to evacuate the air, allowing water to flow to the lance. Dependent on the length of empty tubing the time before the system is at the correct pressure can vary.


Test 2: Pressure and flow

Pressure loss occurs in the form of friction resistance in the piping system and as a consequence height. The pressure was measured with a digital pressure gauge at the connection between the hose and lance.

  • Height: 100 meter
  • Pump pressure: 300 bar
  • Hose: 200 meter, ½ ”
  • Nozzle: 2,3 mm

Result: Nozzle pressure: 229.5 bar

  • Hight: 100 meter
  • Pump pressure: 300 bar
  • Hose: 280 meter, ½ ”
  • Nozzle: 2,3 mm

Result: Nozzle pressure: 214 bar

Test 3: Movement of abrasiv

  • Height: 100 meter
  • Pump pressure: 300 bar
  • Hose: 200 meter, ½ ”
  • Nozzle: 2,3 mm


The test was conducted with the hose connected to a " jig "  with a 2.3 mm nozzle. After the nozzle discharges the water at a " dead end " outlet position, resulting in all the recoil force beeing neutralized.

The color of water indicates that abrasive flow was completely normal and unaffected by the height difference. Abrasive also seemed to be distributed evenly without any visible variations


Test 4: Accumulation of abrasiv during stops

As the hose is pulled completely vertically it could be assumed that the abrasive would move down, under gravity when system is paused, and accumulate at the bottom where the hose turns into a more horizontal position.

Situation when hose is almost in an vertical position during operation.

The tests clearly showed that an increased abrasive flow was noted, however, this did not affect the system by causing a so-called nozzle blockage. The increased abrasive flow passed with a noticeable darker color and then return to the normal lighter color.

Based on this test, it is concluded that it will not be necessary to prepare a special routine for pre cleaning when used at high elevations above the position of the pump.

Test 5: Experience from establishing on heights

Experience of establishing itself with the Cobra at height is limited, therefore both CCS and RSG invested time in this opportunity to learn lessons and create knowledge.


This approach to establish himself with the Cobra at high altitude felt safe and effective. Access to the open pit is of course crucial to this way of pulling the hose but the option to pull the hose up the spiral staircase had certainly been more cumbersome, laborious and time-consuming.

Cold Cut Systems AB - in collaboration with Räddningstjänsten Storgöteborg.

Räddningstjänsten Storgöteborg

>> Read more about their job at - Cutting Extinguishing Tactic.

More high rise tests?

>> Read about our Cobra high rise test together with Rotterdam-Rijnmond Brandweer, NL

Main contact at Cold Cut Systems:

Johan Biörsmark johan.biorsmark@coldcutsystems.com

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