CALVERT -- "Keep moving" is the imperative on the steel coating line that ThyssenKrupp AG opened last week.
ThyssenKrupp coats the steel in molten zinc to prevent corrosion, and also heats the metal, softening its so that customers can stamp out parts. The line is the last major process on the carbon steel side of the $5 billion complex to begin operation.
It is the first of four hot-dip galvanizing lines to be built inside two towering buildings visible from U.S. 43. ThyssenKrupp plans to start the second line later this month, followed by the third in June and the fourth in August.
Making galvanized steel is a key step toward supplying automakers, one of the key goals that Germany's largest steelmaker has for its first U.S. plant.
"This is the bulk of what the automotive industry is going to buy," said Bob Holt, vice president of sales and marketing for ThyssenKrupp Steel USA.
ThyssenKrupp will also sell galvanized material for use in siding and roofing, appliances, metal furniture and air ducts.
It will take months for the plant to demonstrate that it has achieved the consistent quality and production volume demanded by automakers. During that time, officials said most sales will be to construction and service centers -- distributors who act as middlemen for smaller steel users.
The carbon steel unit, which has nearly 1,600 workers, shares the complex on the Mobile-Washington county line with the stainless unit, which has nearly 400 workers. ThyssenKrupp plans to ultimately employ 2,700 people in Calvert.
Carbon steel began production in July, taking slabs shipped from overseas and rolling them into coils.
The galvanizing line is a further step, taking coils of cold-rolled steel and unwinding them again.
In the newest line, a constant flow is required through the furnace that heats the steel to 875 degrees and through the molten zinc bath that follows. Stopping the line means steel in those areas may become unusable.
That's expensive, said Kevin Siebeneck, one of the hot-dip galvanizing managers. Stopping the flow can mean an entire coil of steel -- worth $12,000 to $20,000 on the open market -- could be ruined.
But steel doesn't arrive from cold rolling mill in one long sheet. Coils have to be unrolled one at a time and then welded together. Similarly, coils have to be wound up one at a time on the finished end.
To allow for the stops and starts of coiling, the line has a series of loopers. They build up reserves of steel, allowing a constant flow in the middle.
At maximum speed of almost 200 yards per minute, workers have about two minutes to complete a weld at the front of the line before the reserve runs out, Siebeneck said. As the end of the coil nears, the steel slows and the looping machinery begins sinking from the towering ceiling toward the floor -- a dramatic visual reminder that the clock is running on the switch.