Lidköping Energi’s heating plant is located by the shores of Vänern, Sweden’s largest lake. The heating plant produces heat and electricity from waste, and supplies district heating to 60% of industries and 95% of households and in Lidköping’s urban area, which has 26 000 inhabitants. The steam generated in the process produces electricity sufficient for 5000 households.
The place for today’s job is a fireplace for district heating. Through waterjetting, cracked concrete and areas with thin concrete will be removed from the walls. In the floor heat pipes are embedded in 1 500 mm (59 inches) of concrete. When the concrete is removed new heat pipes will be installed and new concrete cast in place.
Delete group has been commissioned to remove the concrete. They are one of the Nordic region’s leading full-service companies in construction and industrial remediation with services such as waterjetting, sludge suction and chemical cleaning. They have been in the industry since 2010 and has today approximately 800 employees in Sweden and Finland.
One of them is operator, Kjell Petersson. He puts on both the red jacket and trousers from the new collection of protective clothing, EliteOperator. After walking around for a while, he nods in approvement.
”They feel easier to put on and easier to move around in,” says Kjell Petersson.
TST Sweden’s EliteOperator, is the company´s next generation of ultra high pressure clothing. The new product line has the same high level of protection as their previous top of the line clothing (3000 bar / 43 500 psi), but with a whole new level of comfort and freedom of movement. The new products have been made possible thanks to TST’s new technique and philosophy, Athletic Design, which makes it easier to walk, bend down, crouch, bend arms and legs, squat, climb ladders, walk stairs and everything else an operator does during a work shift.
The new Athletic Design includes a lot of new design elements to improve the clothing’s compliance. For example, the protective areas, with Dyneema®, has been divided into several parts to better follow the body’s movements and a wedge-shaped part has been inserted in the armpit area to provide the garments with increased mobility. Other new features include that their trousers and overalls have both been equipped with pre-bent knees for added flexibility and all areas without protection are made of a stretch fabric for both increased mobility and comfort.
When Kjell is ready, he walks towards the workplace, up a couple of steel stairs, through the heating plant and then up a few stairs again. Then he crawls through a narrow hatch covered with black soot to enter his ”office”, the fireplace for district heating. The walls were initially covered with 50 to 200 mm (2 to 8 inches) concrete. Now there are cracks in some places and in others the concrete is much thinner or gone altogether. Everything that does not look intact, Kjell will remove with his waterjet gun. And so, the main part of his working day commences.
There are three operators working each pump and they work for one hour at a time, four sessions per day and operator. One team works for twelve hours and then they are replaced by a new team with three new operators that works for another twelve hours meaning that they work around the clock. Some jobs last for two weeks, others for a few days. In addition to Kjell, the operators Adam Stensson and Sebastian Virtanen are part of the work team.
”We started here yesterday, and I think we are done either today or tomorrow,” says Sebastian Virtanen.
As soon as Kjell starts operating the watergun, pieces of concrete, soot, dirt, and water start flying around the cramped space. The water used to remove the concrete holds a pressure of 2,800 bar / 40,000 psi and demands a lot from the operator. This is the exact opposite of a day in an air-conditioned office, sitting on an ergonomic chair in front of a computer with a hot cup of coffee. Waterjetting is strenuous work which requires both body mass, strength, and endurance. It’s a tough job, but someone has to do it.
“Someone said that it’s like having 40 kg (88 lb) against your shoulder pushing you backwards. If you stand on a bit of gravelly ground, you’ll go backwards”, says Adam Stensson.
”We use this high pressure because you want to get behind the cracked concrete as quickly as possible, so that you can ’blow away’ the loose concrete,” says Sebastian Virtanen.
WHAT WAS IT LIKE TO WORK IN THE NEW PROTECTIVE CLOTHING, ELITEOPERATOR?
Kjell: “They were much lighter and more mobile than I’m used to. Even though they were brand new. The old overall was awkward and stiff from the start and softened after a while. But these new ones were comfortable straight away.”
HOW DO YOU FEEL THE NEW DESIGN AFFECTED YOUR MOBILITY AND COMFORT?
Kjell: “The protective surface felt more compliant than before and followed the body’s movements better. You could tell that the knees were pre-bent and that there is a new design on the garments. Stretch material in certain parts of the clothes, made it easier to move and twist my body.”
WERE THE CLOTHES HEAVY TO WORK IN?
Sebastian: “At least they didn’t feel heavy. It might have something to do with mobility and comfort. When you are more mobile, the clothes feel lighter.”
DO THEY FEEL COMFORTABLE?
Kjell: “I usually don’t think about comfort when I’m working. So, they’re probably comfortable, because I guess I would think about it if the clothes weren’t comfortable. ”
WHERE THEY WARM TO WORK IN?
Sebastian: “You never really get rid of the heat. It gets hot when it’s heavy work, you basically get hot as soon as you start working. That’s why we like the ventilation function and usually use it all year round.”
Ventilation, which is an option for TST’s Trousers and Overall, allows compressed air to flow through the clothing, cooling the operator during the entire work shift. To make maximum use of the ventilation a continued airflow of 250–400 l / minute (9–14 CFM) at 7 bar is required. Also, smaller compressors can be used if there is a possibility to regulate the airflow.
If compressed air is not an option, then TST’s Cooling Vest is a good alternative. The vest absorbs heat from the body and provides an effective, but gentle cooling. The technology is unique and based on special energy TEMPTECH® elements. The elements absorb heat form the body, providing an effective and gentle cooling for 90 minutes at 60°C and four hours at 45°C. The elements recharge without an external energy source: 2–3 hours in 22°C, 30 minutes in 8°C and just 5–10 minutes in a freezer or in iced water.
After an hour of hard work, Kjell crawls out through the narrow door. The clothes are wet and dirty on the outside. He takes off his helmet and exposes a sweaty, tired, but happy face. He seems to be pleased with both the job and the new protective clothing EliteOperator. We follow him to the work stall where he changes, which looks quite easy. Then the whole team gather around a table in the break room. When everyone has a cup of coffee in their hand, we start discussing the work shift and the new collection.
DID YOU STAY DRY IN THE NEW CLOTHES?
Adam: “You get sweaty. But that comes from your body. On the outside, the clothes stopped the water, so in that sense I stayed dry.”
SOMETHING THAT WASN’T GOOD? WHAT CAN BE IMPROVED?
Adam: “I thought EliteOperator was very good to work in. Something that would be nice to have would be a small pocket you can close, somewhere on the pants, with room for a nozzle. Because sometimes you need to change the nozzle during a job.”
TST’s representative on site says that their R & D has talked about adding a pocket, but that it was opted out for security reasons.
WHO DECIDES WHICH PRODUCTS YOU SHOULD USE?
Kjell: “We decide for ourselves what equipment we should have. I have previously only used the overalls and trousers and a vest.” The overall is unfortunately often used without a vest. It is good to keep in mind that TST’s overall has no protection on the upper body. It must therefore be used together with the vest. Someone who knows what it’s like to be hit by a waterjet is Adam. A few years ago, he had an accident when he unintentionally shot himself in the foot with a water jet at 800 bar/11 600 psi. He wore ordinary rubber boots on his feet without any added protection.
A colleague had to drive Adam to the hospital. The sharp beam made only a small hole in the boot and the wound was not large either. However, due to the risk of infection by injecting contaminated water with a waterjet, the doctors had to make a 15 cm long incision on each side of the lower leg to drain the dirty water and clean the wound. Adam shows a picture from the hospital. Let’s just say, without going into any details, that’s not a picture we want to publish here. After the accident Adam had to stay in the hospital for a week before he finally could go home again. A clear reminder on how important it is to use the right protective equipment when working with water jetting.
TST Sweden article published in WJTA Jet News, August/September 2022, reprinted with permission.