Old Cedar Bridge

[Mdcastle]

It's been a long time coming, but work on the Old Cedar Bridge over Long Meadow Lake is underway. It was closed to motorized vehicles in 1993 (cutting off access to three of the last four farms in the city), then to completely in 2002. (I got my driver's license in 1993 so I don't recall if I ever personally drove over it, but I did many times as a passenger.

Replacing it has been tied up due to lack of funding and lack of consensus. Bloomington has always been a reluctant owner of what it sees as an expensive regional amenity, and would still like someone else to take it. The original thought was to replace it with an earthen causeway over a gas line, which was rejected by the federal government. Bloomington's preferred solution then turned to replacing it with a modern pedestrian bridge, and the idea was floated around of plopping the trusses onto it as decoration. Finally clear direction and funding came from above, so rehabilitation is in progress.

So the scope of the project is:
1) Rehabilitating the bridge to allow pedestrians and the ocassional maintenance or emergency vehicle.
2) Substantially improving the parking lot area, including a sheltered picnic area and modern restrooms.
3) Reconstruction Old Cedar Ave. There will be a nonprotected bicycle lane going uphill, and a sharrow going downhill.

Some of the decisions that were made include:

Piers: After investigation revealed that although the foundations were good, the piers themselves needed the vast majority of the visible concrete replaced, and doing so might even be a safety hazard to workers, so the piers will be completely demolished and rebuilt to replicate the old ones, including the wood forms. To accomplish that shoring towers are now being built to lift the entire bridge off the piers.

Deck: The original deck was blacktop over concrete. Later the concrete was replaced with wood to reduce weight. The new deck will be a lightweight concrete. Most of the steel members below the deck are in bad shape. It was decided to scrap them all and rebuild with fewer than original since they are not highly visible and not as many are needed without heavy traffic and modern construction materials.

Superstructure: Most of the higher components are in pretty good shape, and only one major piece needs complete replacement. Some bent pieces, while OK structurally, will be straightened as not to alarm people looking at them. Those closer to the deck are worse, and will require a lot of patching and replacement.

Lighting: The original bridge had no lights. They discussed installing lighting, and decided against it due to in-authenticity and that the area was "closed after dark" anyway (although you can get to the Mn/DOT river crossing without leaving city ROW and entering the wildlife refuge.) There used to be an "Area Closed After Dark" sign on the bridge.

Railing- the railing always was those gas pipes. They've been hit and replaced so many times it's impossible to determine what's original so they'll all be replaced, with cables in-between to meet modern standards.

Fasteners- The same issue as the Stillwater Bridge is to how to replace rivets. Engineering standards prohibit rivets in certain locations, and riveters aren't exactly common. The plan to use bolts that look like rivets on one side, "authentic" end towards the inside so you'll see the hex nuts looking on the outside, and rivets for a few places where they're allowed and can be installed in a shop.

Color- It's now a rusty brown, but it will be repainted it's original grey.

So far the projects off to a rough start. To build the temporary bridge CenturyLink had to move their fiber optic cable. The boring machine broke, and it broke under a significant oak tree that they couldn't cut down to get it, so they had to start again.

http://oldcedarbridge.com/

[Mdcastle]

image by North Star Highways, on Flickr
IMG_8492 by North Star Highways, on Flickr