Energy Absorption Calculations

The tables below give the holding power of just one SlowStop Bollard impacts at 20" above ground with a frontal impact.  A rigid connection of 2 SlowStop Bollards gives the double holding power when connected within 40".  Ask our advice.

SlowStop® Type 1 Mass (lb.) Speed (mph)
Tube diameter ø3"x 0.2" 1100 5.7
1,195 ft.-lb. 1760 4.5
  2640 3.7
  3300 3.3

 

SlowStop® Type 2 Mass (lb.) Speed (mph)
Tube diameter ø4" x 0.25" 1100 7.3
1,967 ft.-lb. 1760 5.7
  2640 4.7
  3300 4.2
  4400 3.7
  5500 3.2

 

SlowStop® Type 3 Mass (lb. Speed (mph)
Tube diameter ø6.63" x 0.32" 1100 16.2
9,536 ft.-lb. 1760 12.7
  2640 10.4
  3300 9.3
  4400 8.1
  5500 7.2
  6600 6.6
  7700 6.1
  8800 5.7
  11000 5.1
  13200 4.7
  17600 4.0
  22000 3.6


Calculation of the kinetic energy (in ft.-lb.) for a given mass in pounds and a velocity in fps (1 mph = 1.46 fps), with an impact height of 20"

 

Kinetic energy from a moving object: Ekin = 0.5*(m/32.2)*v^2
Eabs ; Ekin = energy (ft.-lb.)
m = mass of the object (lb.)

 

Test results by the TÜV-TNO report, impact height on 500 mm (20")
Type 1 => Eabs= 1,195 ft.-lb.
Type 2 => Eabs= 1,967 ft.-lb.
Type 3 => Eabs= 9,536 ft.-lb.
(For lower impacts, strength increases, e.g. Type 1 at 12" = 20"/12" = 1.67 x 1,195 ft.-lb. = 1,991 ft.-lb

Resources

So far we’ve installed several of the bollards and have been impressed with the durability. We will be installing the remainder in higher traffic, problem areas in the near future.

- Glenn A.

We love them (SlowStop Bollards) and so do the clients.

- Mike D.