motorized equipment---several million dollars' worth of roaring diesels---had stopped only minutes at a time, mainly for refueling or relieving crews. It was work which air travelers never saw at close hand because no aircraft used a fresh-cleared runway until the surface had been inspected and declared safe. Standards were exacting. Half an inch of slush or three inches of powdery snow were maximums allowable for jets. More than that would be sucked into engines and endanger operation.
It was a pity, Mel Bakersfeld reflected, that runway snow teams were not more on public view. The sight was spectacular and stirring. Even now, in storm and darkness, approaching the massed equipment from the rear, the effect was impressive. Giant columns of snow cascaded to the right in arcs of a hundred and fifty feet. The arcs were framed in vehicle searchlights, and shimmered from the added color of some twenty revolving beacons---one on the roof of each vehicle in the group.
Airport men called the group a Conga Line.
It had a head, a tail, a body, and an entourage, and it progressed down a runway with the precision of choreography.
A convoy leader was the head. He was a senior foreman from airport maintenance and drove an airport car---bright yellow, like all other equipment in the Line. The leader set the Conga Line pace, which was usually fast. He had two radios and remained permanently in touch with the Snow Desk and Air Traffic Control. By a system of lights, he could signal drivers following---green for "speed up," amber for "maintain pace," red for "slow down," and flashing red for "stop." He was required to carry in his head a detailed map of the airport, and must know precisely where he was, even on the darkest night, as now.
Behind the convoy leader, its driver, like an orchestra's first violinist, was the number one plow---tonight a mammoth Oshkosh with a big main blade ahead, and a wing blade to the side. To the rear of number one plow, and on its right, was number two. The first plow heaved the snow aside; the second accepted the load from the first and, adding more, heaved both lots farther.
Then came a Snowbiast, in echelon with the plows, six hundred roaring horsepower strong. A Snowblast cost sixty thousand dollars and was the Cadillac of snow clearance. With mighty blowers it engulfed the snow which both plows piled, and hurled it in a herculean arc beyond the runway's edge.
In a second echelon, farther to the right, were two more plows, a second Snowblast.
After the plows and Snowblasts came the graders---five in line abreast, with plow blades down to clear any mounds the front plows missed. The graders towed revolving brushes, each sixteen feet wide and independently diesel powered. The brushes scoured the runway surface like monstrous yard brooms.
Next were sanders. Where the eleven vehicles ahead had cleared, three hulking FWD trucks, with hoppers holding fourteen cubic yards apiece, spread sand out evenly.
The sand was special. Elsewhere around the airport, on roadways and areas which the public used, salt was added to the sand as a means of melting ice. But never for aeronautical areas. Salt corroded metal, shortening its life, and airplanes were treated with more respect than cars.
Last in the Conga Line itself---"tail-end Charlie"---was an assistant foreman in a second car. His job was to insure that the line stayed intact and to chivvy stragglers. He was in radio touch with the convoy leader, often out of sight ahead in snow and darkness.
Finally came the entourage---a standby plow, in case one faltered in the Line; a service truck with a detail of mechanics; refueling tankers---diesel and gasoline; and---when summoned by radio at appointed times---a coffee and doughnut wagon.
Mel accelerated around the entourage and positioned his car alongside the assistant foreman's. His arrival was noticed. He heard the convoy leader notified by radio, "Mr. Bakersfeld just joined us."
The Line was moving fast---close to forty miles an hour instead of its usual twenty-five. The leader had probably speeded up because of the expected wind shift and the need to have the runway open soon.
Switching his radio to ATC ground frequency, Mel heard the convoy leader call the tower, "...on one seven, left, approaching intersection with runway two five. Request clearance over intersection."
Runway two five was an active runway, now in use.
"Convoy leader from ground control, hold short of the intersection. We have two flights on final approach. You may not, repeat, not, cross runway intersection. Acknowledge."
The voice from the tower