Modern engineering in play at Greenup Locks
PDT Staff Writer
LLOYD, Ky. — Located only 15 miles southeast and upriver from Portsmouth, Greenup Locks and Dam was built in 1959 and, like anything else that has reached its golden age, it needs proper maintenance.
Workers from the U.S. Army Corps of Engineers and contractors have been giving the locks a $12 million face lift to ensure the steady flow of shipping that makes Greenup the eighth busiest lock in the country, continues for another generation.
On June 11, on-site work began to replace the up-river set of hydraulic doors of the main lock chamber known as a miter gate, but the manufacturing and planning began much earlier.
The dam history
According the U.S. Army Corp of Engineers, Greenup Locks and Dam started operating its lock system in 1959 and saw the dam portion completed in 1962.
The structure has two lock chambers, one considered the main lock and the other an auxiliary. The locks have seen heavy barge traffic that has worn certain mechanical aspects of the system down.
In 2003, the dam suffered what the engineers term an “Outage” when the main chamber had a mechanical failure and it happened again in 2010. Age and frequent use were the culprits of both outages.
“You are constantly cycling the load in that gate it causes a lot of fatigue,” Project manager from the Huntington office of the U.S. Army Corps of Engineers Mike Keathley said. “It’s like taking a coat hanger. You keep bending it and bending it that eventually it breaks.”
Steve Hann, the Operations and Maintenance Project Engineer overseeing the Greenup project said the economic impact of unplanned maintenance on the dam made the today’s work necessary.
“In 2003 when we had that failure and in 2010, the (towing) industry wasn’t ready. They ship on a need basis,” Hann said. “In 2003 it came to the point that some of the smaller power plants were going to shut down if we didn’t open back up because they didn’t have any coal.”
Reasons for repairs
With an annual average of 65 million tons of materials moving through the Greenup Locks and many industries dependant on its operation, fixing the dated miter gates of the 1,200-feet by 110-feet main chamber became a priority for the engineers.
“One of our roles is ensuring proper navigation and the continuation of commerce in the region,” Brian Maka, Public Relations Officer for the Huntington office of the Corps of Engineers. “In 2010, the 26-day outage delayed 258 tows and cost the towing industry an estimated $5.2 million.”
According to Keathley, the direct cost to the towing industry over the last 12 years due to outages at Greenup is estimated at $30 million.
“The industry hasn’t had time to plan for it and get ahead. So you have an emergency closure and it’s like shutting down the interstate,” he said.
The wear on the gates at either end of main lock chamber was becoming more than temporary fixes could mend.
“These gates take a huge amount of static load,” Greenup Lockmaster Eric Dolly said. “It’s 1,800 tons of pressure when the gates are closed holding back 65 miles of river.”
Part of Keathley’s job is to study and project future needs of the lock system and analyze what he finds.
“When it is breaking down every two to three years, we have to look at our alternatives,” Keathley said. “One of those alternatives is to upgrade the miter gates because we know that is the component that most frequently leads to outages of our lock chamber. We initiated the program of replacing the gates and that is what Steve (Hann) is doing.”
Hann and his crew had a some idea of the work they would be doing at Greenup, but the project on the main chamber is still a groundbreaking piece of engineering.
“This is the first time we have done this in a main chamber. We went to Meldahl Locks and Dam outside Cincinnati to replace the gates on an auxiliary chamber to get the process down,” Hann said. “We learned where we could cut costs and time during that project and this is the first go-around with a main chamber and I think things have gone well.”
It’s difficult to properly judge the scale of the locks without seeing the work being done, but numbers can paint a pretty enormous picture.
Each miter gate has two “leaves” and each of those weighs 290 tons. According to Hann, the 60-foot by 60-foot gates were manufactured by Steward Machine Co. in Alabama, trucked to St. Louis where they were welded together and brought to Greenup via barge.
Before the arrival of the new gates, the old ones had to be removed.
“We started on June 11 and the job entailed taking the old gates out and the embedded steal plate that runs up the wall,” Hann said. “We cut all of that out and replaced it all with new, up-to-date design standards. This gate should have a longer life span than the original.”
Installation of the gates wasn’t like replacing a closet door or even a garage door, rather it was more similar to installing the gates of Troy. A special piece of equipment, essentially a giant, self-ballasting crane known as “The Shreve” was needed to raise the gates and slide them into their new home on the up-river side of the main chamber. The Shreve’s crane reaches a towering 228 feet into the air.
“It is a division asset. Owned by the Great Lakes-Ohio Division. Basically we go get it when we need it and bring it to us,” Hann said. “It is made specifically for heavy lifts on the river. On a good day it will lift over 400 tons on a short radius. It’s made specifically for this application. It’s mounted on a barge and we push it to where we need it.”
Also being replaced were the apparatuses on which the gates swing. Hann said the bottom hinges acts like a hip socket while the top ones act as an anchor to hold the gate in place.
For such an large piece of equipment, the specificity of operation means the engineers earn their pay.
“Just like a door in your house, you have to get it squared up so it can open, close and lock,” Hann said. “Our guys are fine-tuning the gates so that every time they swing they go to the exact spot. With these structures, we have span within one-eighth of an inch in every plane they must hit when closed.”
A team of 45 highly skilled workers split between two shifts were tasked with 10-hour work days and one day off for every 13 days on. With the proper equipment and crew, the new gates are set to be operational Oct. 6.
“They are in place now and we are just doing final adjustments to get everything to the point that Mr. Dolly is happy, Hann said. “We are about a week and a half from being finished.”
With regular river traffic being routed through the auxiliary lock, the time to pass through has increased from the normal rate of one hour to seven hours. According to Keathley, the auxiliary lock is half the size, 600 feet, of the main lock, causing typical towboats to split their loads between two lockages.
The increase in travel time caused the Corps of Engineers and the towing industry to work ahead.
“The industry can plan for this outage and we are on schedule within the time frame. Before an outage happens they bust their butts and ship all kinds of coal and stockpile it and ride the delay out,” Hann said. “This time they stockpiled and helped each other and it’s down to a seven hour average. In the previous years it would get up to 24 or 48 hours during emergency outages because you had so many boats sitting and waiting.”
Even with the delays, the locks have remained very active.
“We have had 1,200 commercial tows and 2,000 lockages during this outage,” Dolly said.
The workload of Greenup Locks gives a glance at the state of the economy.
“At Greenup we averaged 65 tons last year. Peak tonnage 72 million tons in 2000,” Keathley said. “It has tapered off because of the state of the economy. The low point was 50 million tons and now we are starting to rebound a little bit.”
From 2000 to 2011 Greenup averaged 64 million tons of materials, the majority of it coal, passing through its gates making it one of the ten busiest locks out of the 198 in the country.
Future of Greenup Locks and Dam
Repairs on the lower half of the Greenup Lock in 2010 enabled the engineers to focus their attention on the upper gates, but it will not be long before the lower gates need to be replaced. While the river traffic jam will alleviate come the first week of October, it will return in 2014.
According to Hann, the idea is to get ahead of issues at the locks before they arise.
“What we are trying to do is get ahead of the maintenance curve,” he said. “(The Ohio River locks) are all aging. Even the ones that are lower tonnage are getting to the point that they need to be fixed. We are going to have to fix them. The problems we are seeing in the older ones are starting to creep into the newer ones. So I have job security for a lot of years.”
Keathley is looking at other aspects of the dam to ensure it serves its vital purpose in the region’s infrastructure.
“We have a reliability study going on the dam and a possible rehab on the dam. It’s 60 years old,” Keathley said. “We don’t have any current problems with the dam, but it’s realistic to expect that once it approaches 70, 75 years it’s going to have incidents. What we don’t want that to happen and lose the dam.”
The Huntington District of the U.S. Army Corps of Engineers is one of 45 districts worldwide. It is responsible for 311 miles of the Ohio River and its tributaries. The district encompasses 45,000 square miles in parts of five states.
Bob Strickley can be reached at 353-3101, ext. 203, or email@example.com.
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