Sky High

Heat, high-pressure water and a lot of skill enable a German company to clean the historic Space Needle in Seattle

Air pollution, algae, bird droppings, dirt and grease from three outside elevators had accumulated on the 605-foot-tall Space Needle in Seattle since it was painted in 1998. The grime was visible from the ground or as visitors rode the elevators to and from the observation deck and revolving SkyCity restaurant.

After cleaning the Statue of Liberty, Washington Monument, Mount Rushmore and more than 80 historical monuments worldwide, Kärcher GmbH & Co. KG in Winnenden, Germany, wanted another project in the United States. Officials contacted Space Needle LLC in Seattle, offering to clean its landmark for free. The opportunity would provide feedback to enhance the company’s research, development and manufacture of new products.

The challenges Kärcher supervisor Thorsten Möwes and Space Needle engineers faced in planning, testing and analysis included the structure’s tripod shape, access points, protecting the surrounding city and – for the first time in the company’s history – working at night. Three years of planning concluded when rope-access professionals cleaned the Space Needle in eight weeks using only hot water and high-pressure jets.

Groundwork

Two of Möwes’ first three visits to the Space Needle involved test cleanings to determine the best approach, machines and nozzles. Chemicals would remove the grime faster, but it was impossible to protect the block occupied by the Space Needle from them. Overspray, sometimes carried on gusty winds, could land on nearby buildings, vehicles and vegetation.

“We decided to use plain hot water, which would have no effect on the environment, but certainly could damage the paint or its color,” says Möwes. “The paint manufacturer said it could withstand 200-degrees Fahrenheit, so we chose 194 degrees.”

For two-thirds of the project, industrial climbers would rappel 492 feet. Kärcher’s longest high-pressure hose was 60 feet, but coupling more than five together reduced velocity with each additional inch. Möwes asked Kärcher-USA in Camas, Wash., to manufacture three continuous hoses 450 feet long. The company also provided all other equipment, including three HDS 5.0/30-4S Ec electric hot-water high-pressure washers.

“By the time water at 3,000 psi travels 450 feet through a hose, it leaves the nozzle at 2,500 psi and reaches the surface at about 400 psi,” says Möwes. “Further tests showed that our 40-degree flat jet nozzles and short spray wands with water at 5 gpm would remove the grimy film without damaging the paint.”

Because it was too expensive to erect scaffolding around the landmark, Möwes hired rope-access technicians Reuben Shelton, Nathan Schuster and Matt Henry from Skala Group in Reno, Nev. They were experienced using high-pressure jetters and trained to national and international rope-access standards. Brian Warshow, the required Level 3 supervisor from Skala, and assistant Matt Waskiewicz oversaw safety and monitored the lines and rappelling equipment.

“This type of rappelling has nothing to do with mountain climbing,” Möwes explains. “Moun-taineers have only one line. Industrial climbers have a working line and a safety line. We wear a full-body harness with ascending and descending devices to move up, down and around the structure. We also have a second rope for backup, making this type of climbing safe and effective at any height.”

The Space Needle depends on the 1.3 million tourists who visit annually, so closing it was not an option. Cleaning occurred from 11 p.m. to 6 a.m., but the structure is so well lighted that it was almost like working in daylight. The team wore helmet lamps mainly to illuminate what was in shadow.

Blown in the wind

The first two nights involved using the service elevator to bring jetters, hoses, trolleys and other equipment to the observation deck (O-Deck) one level above the restaurant. Cleaning began on the third night. The area around the Space Needle was taped off, and its security team maintained camera surveillance. “Everything on our rigging and harnesses is secured with lines so nothing can fall down, but we’re human and accidents happen,” says Möwes. “We want no one in that work area except us.”

Starting at the O-Deck, the team cleaned down to the restaurant. Trolleys fixed on the deck served as anchor points, enabling them to move easily around the entire five-level top house dome. Their nightly progress depended on the amount of dirt encountered. Surfaces near the elevators were the worst.

Their next access, through a restaurant window 500 feet above Seattle, allowed them to clean down to a stairwell hatch. “The pressure washers remained on the O-Deck, where we had water and electricity,” says Möwes.

In three weeks, the team neared the core of the structure – the halfway point. “Seventy percent of the time, I stood beside the machines and organized everything from there,” says Möwes, who holds a Level 1 worker’s license. “I also inspected the cleaned surfaces, and if the technicians had problems I went out and told them what to do.” Doug Yates and Derrick Knight from Kärcher-USA helped maintain the pressure washers.

Wind gusts of 30 mph or higher slowed the work. Two days with winds stronger than 50 mph stopped it. “Wind is a bigger concern when we’re hanging free of the structure or on long lines,” says Möwes. “It isn’t such a problem if we’re close to a surface or on short lines.”

Every rope-access technician could decide at what level he was uncomfortable with the wind and go inside. Work also stopped if Warshow spotted lightning on the horizon or 30 miles away.

The team’s third access point was the stairwell hatch, a window opening to a fenced platform. “When we finished that section, we were two-thirds of the way down,” says Möwes. “Our last phase was moving the machines to the 200-foot deck, our only other source of water and electricity, and working to the base of the Space Needle.” Seattle’s most popular tourist attraction was once again squeaky clean.



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