The Annual Inspection of the Large Lock
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Looking west over large lock during inspection |
The large lock is undergoing its annual
inspection and maintenance which should conclude by November 20. This
is also referred to as the Corps' Annual Cell Phone Scavenger Hunt
due to the number of phones recovered when the lock is drained.
Numerous other types of objects are also found but cell phones are
among the most common. As the water is drained out, fish and other
marine life have to be carefully moved to exit the lock before it
completely emptied. This year found the usual assortment of fish,
starfish, seals, otters, and an octopus. All removed safely to the
sound so the work could begin.
The locks are each drained once a year
to inspect all critical components and perform some maintenance
necessary for the fish migration which is a crucial part of the Locks
mission. To begin the process, emergency gates are lowered in
sections by crane inside the east gates.
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One section of emergency gate being lowered into position |
Once
these are solidly in place a scaffold will be assembled on the lock
wall and then lowered by crane to rest on the lock floor. While the
crane is still providing support for the scaffold, two personnel climb
down the scaffold to secure the locking mechanism at the bottom of the
legs. These individuals are called the “Short Straw” men. The
scaffolding now secured below, the crane releases its hold and the
scaffold will then be securely fastened against the lock wall for the
rest of the crew to descend to perform their daily tasks.
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"Short Straw" men head down |
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Scaffold assembled |
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Lowering scaffold |
All
working components of the lock will be inspected and if necessary,
repaired. For the most part, it's routine maintenance which is required.
The locks were originally finished in 1916 and the aging process means
attention to detail is critical. Over the years improvements were made,
new technology replacing old technology, but by and large it is looks
substantially the same today as it did when completed. Most of the
visible changes have been made for safety reasons, hand and guard rails,
lighting, etc., and the mechanical upgrades are largely well out of
sight of the visitors.
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Spot welding on gate |
The
culverts, through which the water moves from lakeside to sound, become
encrusted with barnacles just as the lock walls do. Because many of the
salmon will use them for their migration crews will spend days scraping
the barnacles from the culvert walls to prevent harm to the salmon as
they brush against the side. Some estimate that as much as 47% of the
salmon will use the locks instead of the fish ladder to reach their
spawning grounds but it is widely believed this number to be highly
inflated. It is probably boaters leaning over the sides of the boats
while locking through that deposits most of the cell phones, with the
rest simply being dropped by visitors on foot while taking pics or
videos. But if you can hang onto your smart phones you can get some
great shots of salmon leaping and the occasional seal among the boats
during the height of the salmon season. There was once a minke whale who
ventured in, but that's a story for another day.
The inspection should be finished by around November 20. While
the large lock is under maintenance, the smaller lock is still
operational so visitors can still enjoy watching the process. The large
lock will provide only a few glimpses of the work underway but you can
always watch the birds fighting over barnacle meat and wrigglers they
are feeding upon.
Here are some pics of the maintenance in progress. You can click on any to see an enlarged view.
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The large lock drained. |
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Working with the gates. |
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Small bulldozer lowered into lock to scoop mud and debris and scrape barnacles from walls. | | | | |
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An idea of the scale of the lock. |
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The inside gates open. |
November 20, 2012 (Update)
The
next two photos were taken Nov. 20 by Corps employee Katie Mcgillvray at
high tide. With all the rain we received it contributed to the 12' tide
level and you can see the water seeping through the outer lock wall.
The work has been finished and the large lock is back in operation. For
those who did not see the locks during this maintenance period you
can mark your calendars for next November and see the lock as you rarely
can.
A Look Back
The two pictures below are of some
interest as well. Notice the water spilling over the gates and into the
emptied lock and the scaffolding showing in the right lower corner. We
are still attempting to gather more information on when exactly this
might have been taken. A search through old issues of the Seattle Times
turned up a reference to water spilling over the gates during a storm on
Jan. 27, 1983. The large lock is usually drained in November however so
this raised a few questions. Was the lock being inspected at a
different time of year or was there another reason to empty and inspect
it so soon after the November event? The same article mentioned that the
tide was measured at 14.8 ft which tied a record previously set in
1977. These were the two largest high tides recorded since 1898. It
might be worth noting the high tides in the upcoming months and making a
trip to the locks. You never know but you just might see a scene like
these below.
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Jan 27, 1983 ?? |
Below is a link to a past inspection. Enjoy.