Crash attenuators (TMA)
The crash attenuator (TMA) is a cushion that absorbs the shock at a collision. One could call it a crushing zone. The crash attenuator is positioned upstream of the traffic flow and serves as a shield for the road workers against a possibly intruding vehicle.
At the impact the cushion will crush, deform and absorb the energy of the collision. The energy absorption happens in a controlled way so the driver is not brutally stopped.
There are 2 Types, a 70K and a 100K cushion
The 70K is made and tested for collisions at a speed of 70 km/h, the 100K for 100km/h.
The Stuer-Egghe crash attenuators, signalling board and supporting frame are conform with the models tested by TNO Automotive Crash Safety Centre at DELFT (NL) fulfilling the NCHRP 350 recommended test levels 2-50, 2-51, 2-52 en 2-53 for speeds up to 70 km/h and 3-50, 3-51, 3-52 en 3-53 for speeds up to 100 km/h . (Test methods 51, 52 and 53 have been carried out using a vehicle representative for the European Union, being a MPV)
The crash attenuator has a signalling board with light arrow fitted. The signalling board has diamond grade retroreflective sheeting and the regulatory signs plates.
22 LED luminaries form the light arrow (left - right- cross) and on top there are 2 double LED flash beacons.
Depending on the ambient light the arrow lights will shine harder or weaker. In sunlight the light arrow will shine brighter and dim at night as not to be blinding.
The crash cushion is attached to the truck with a simple system of three anchor points. The attenuator can be attached or disengaged in less than fifteen minutes.
The construction also offers the advantage that the cargo deck of the truck remains free.
The Stuer-Egghe crash attenuator is operated fully automatically from the cabin of the truck. With a mere button push the driver can lower the cushion and activate the signalling board. He chooses the pattern of the light arrow and the directional arrow sign plate points the same way. On the display the adopted positions are shown in feedback.
New: TMA with elevated VMS
For more information, see TMA with elevated VMS