In January 2019, engineering developed a project plan to update the 524 Haul Unit, emphasizing safety, like the updated safety features on the 1548 Haul Unit implemented in 2010.
The 524 Haul Unit facilitates spoil removal for TBM sizes 48SC to 600 and 11 dirt buckets models in both standard and extended lengths.
We released the first 524 Haul Unit in 1977, and several iterations were designed and manufactured before the current day model was developed in 1990. This version has been quite popular – we’ve manufactured and sold 173 units.
The foremost specification to address with the redesign was replacing the reversing contactors with a new permanent magnet AC motor controller and a wireless control pendent. This change essentially means that the new design must have variable speed options (slow, medium, and fast) versus on or off only. If the target price point is met, the third consideration is the option for a fully autonomous mode, so an operator would not be needed on the haul unit for dirt bucket cycling. The final requirement is to incorporate the latest standards for lighting, horn, and braking.
The design team also discussed the option for a non-autonomous version. The models would be identified as 624A for autonomous and 624, as the updated 524 with the newest specifications.
We developed a 624A prototype in 2020. In the Fall of 2020, they set up a tunnel simulation in the east end parking lot to verify the autonomy capabilities. Wood segments and other objects were thrown within the LiDAR sensor’s sight path, and it performed very well, coming to an abrupt stop when these instances occurred.
In March 2021, the 624A was installed in the PCI Roads project tunnel in Eden Prairie, MN. The haul unit performed automated travel in and out of the tunnel, stopping at each end without an operator riding along.
The unit’s acceleration and gradeability will be verified in the next few months, required the 624A to travel on an inclined track and with a loaded dirt bucket to test for load rating. Stay tuned for more!
