M-Lock® Modular Bridge System

Rocla’s popular M-Lock® modular bridge system continues to provide a fast, simple means of bridging small to medium spans using a range of modular precast components. Since 1995 the system has been installed in over 300 locations around Australia.

The system is designed to AS5100 for 7-15m span lengths, in a range of width and crossfall configurations, for SM1600 traffic loads with a 100 yr design life of major components.

The range includes the cost-effective ‘Bolted’ system for lower usage bridges (<1000 AADT) and the higher specification ‘Post-Tensioned’ design. A range of barrier types can be fitted to M-Lock®, and options include 30 degree left or right skew configurations, precast kerbing or provisions for walkways.

The system is pre-engineered and certified, reducing design costs, and the high proportion of precast bolt-together components shortens project timelines, reduces on-site crane and labour requirements and reduces overall project cost and ongoing maintenance requirements.

The system is designed to be used with or without topping materials, and can be installed with varying abutment designs, including a complete precast system including precast headstocks and piles

See the speed-of-installation benefits in this time-lapse video.

Contact the Rocla ‘Bridge and Earth’ team at for any technical assistance, or to book a ‘lunch and learn’ session at a location of your choosing.


  • Rural road bridges
  • Timber bridge replacement
  • Subdivision bridging
  • Pedestrian walkways