The U.S. Army Corps of Engineers, Detroit District
maintenance crew dedicated to the Soo Locks, located at Sault Ste. Marie in the
upper peninsula of Michigan, have arrived at the Buffalo District to repair a
portion of the 100-year old Black Rock Lock, Buffalo, NY.
The maintenance crew, led by Mechanical Engineer Jeff
Harrington, is replacing the upper gudgeon bearing on the lower west miter
gate. The original gate was constructed in 1914 and is supported solely by this
bearing at the top, and the pintle (ball and cup) at the bottom. Each bearing
sees about 78,000 pounds of horizontal force, and the pintle supports the full
vertical weight of the 156,000 pound gate.
The 15-year-old gudgeon bearing to be replaced is a
maintenance free straight bushing, which has a thin low friction liner backed
to bronze, with a stainless steel pin through the middle. Due to the 102 year
old age of the gates and misalignment over the years, for which the straight
bushing is not designed to handle, the bushing’s liner was worn through by the
gate pulling the pin at an angle to the bushing.
The project has been progressing about as smoothly as can be
expected on such an aging structure.
“After the pin was removed, the crew discovered the bearing
was seized to the pin which caused extensive damage to the lower housing. This
was repaired with a structural epoxy, which saved the crew several days of
extra work,” said Buffalo District Project Manager David Mastriano.
The new bearing is a maintenance free spherical bearing
which allows 2 degrees of misalignment. The new custom designed bearing should
last for over 25 years.
The crew will also be adjusting the anchorages to correct
some sagging of the gate and provide a better miter to limit water leakage. All
maintenance work is done with water on the gates to prevent any movement once
the pin is removed. The immense weight of the water prevents the gate from moving
during important maintenance projects such as these.
The project will take approximately four days working 12 hour
shifts to complete; however, impacts to navigation are minimal, as commercial
and recreational navigation is light this time of year.
The Black Rock Lock is a crucial link in the vast system of
interdependent locks, ports, harbors, navigation channels, and navigation
structures that comprise the Great Lakes Navigation System operated by the
Corps of Engineers. Maintenance projects such as these are crucial for
maintaining navigation on the Great Lakes and its infrastructure as a viable,
functional system that is essential to preserving the health and vitality of
the region and Nation.