Replacing A Manhole Riser Ring

Recently, J. Thomas, LTD. was contacted to help with a manhole riser ring replacement in Westminster, Maryland. The township was contacted by a citizen who was complaining about the noise of traffic running over the manhole lid on the street next to their home.

Upon removal of the manhole lid, the maintenance crew discovered that the installed manhole riser ring was mostly rusted through, with massive gaps, that allowed the lid to slam down into the manhole and create the noises. It was also a safety hazard.

Ring 1

The old manhole riser ring is completely rusted through and broken from busy traffic running over the manhole cover.

The crew began to prepare the manhole for removal and replacement of the manhole riser ring. This took some time for asphalt removal and the actual removal of the ring.
The standard ring that the crew was familiar with not only had an adjusting turnbuckle that was designed with two nuts; one for adjusting, one for locking. The crew find that these still come loose over time and are very hard to adjust and lock in place. This could create a safety hazard by forcing the installer to use multiple tools that increases the risk of working over an open manhole.

Ring 2

Once the old manhole riser ring was removed, the crew inspected the ring and found the spot weldments were broken in several places. This allowed water and debris to get in between the ring parts. This creates rust and weakness, combined with the traffic that runs over the manhole; eventually causes breakage.

Ring 3

The installer then used a J. Thomas, LTD. Manhole Riser Ring as a replacement. After the ring was tapped into place, the turnbuckle required a few turns with one tool and minimal force to secure the ring. The total installation time was approximately 90 seconds. The ease of use and quick installation time is critical on state roads with heavy traffic. The installers need to get in and get out quickly for safety reasons and to minimize traffic disruptions.

Ring 4

The J. Thomas, LTD manhole riser ring final installation was completed under two minutes with minimal effort.

Ring 5

The J. Thomas, LTD. Manhole Riser Ring is made from hot-rolled steel with welding around the entire underside of the ring for complete seal, and includes a 3/4” stainless steel turnbuckle. The entire ring is encased in a rust and weather resistant coating. The rings are specifically designed to store in stacks without warping, allowing the installers to easily pull them apart and ensure an accurate fit in the field.