YOKKAICHI, Japan — When lead-lined Japanese military helicopters took to the sky last month to dump water onto the Fukushima Daiichi nuclear power station, Kazunori Hasegawa watched the desperate and highly risky cooling operation on television with dismay.

“It was so inefficient, so inefficient,” recalled Hasegawa, president of Chuo Construction. The Chinook helicopters had to fly high to avoid potentially lethal radiation, and much of the 8,000 gallons they dropped during the day’s operation landed wide of the mark.

He had an idea: Might not two huge German-made contraptions he had sitting outside his office here in Yokkaichi do a better job? The devices, truck-mounted concrete pumps, had maneuverable arms 52 yards long and could blast water directly onto the Tokyo Electric Power Co.’s perilously overheated reactors and spent fuel rods.

“I was ready to move right away,” Hasegawa said. Tokyo Electric, known as Tepco, wasn’t.

More than a month after he offered to help, his machines still hadn’t been put to use. Instead, Tepco, with help from the Japanese government, brought in similar, albeit slightly longer, pump trucks from Germany, China and the United States. Two with especially long arms arrived by air from Los Angeles and Atlanta last week.

The episode illuminates some of the headaches that plagued Japan’s critical early response to the world’s biggest nuclear disaster since Chernobyl. Initially reluctant to acknowledge the gravity of the crisis, Tepco played down the danger as it struggled to keep pace with an escalating and ever-shifting catastrophe at the six-reactor Daiichi complex. The plant had been built to harness complex laws of nuclear physics, but the damage it suffered in the March 11 earthquake-generated tsunami generated a chaos of often mundane logistical problems involving trucks and pumps, fire and water.

A massive operation

Tepco, the world’s largest private electric utility, supplied a third of Japan’s electricity before the quake and has dozens of subsidiaries abroad, including a uranium producer in Canada, a company in Delaware and a shipping firm in the Bahamas. Its size, combined with a rigid top-down hierarchy and a commitment to proven procedure, made the company a steady pillar of Japan’s corporate establishment but crimped its capacity for swift and innovative action.

When radiation spiked dramatically at its Daiichi plant on March 15 after an explosion at reactor unit 3 — one of several blasts at the complex — and the exposure of highly radioactive spent fuel rods, Japan’s Self-Defense Forces sent helicopters to dump water scooped from the sea. An initial attempt on March 16 had to be aborted because radiation was just too high.

On the same day, at Tepco’s Tokyo headquarters, the company’s boss, Masataka Shimizu, vanished. His health cracking under the strain, he quit an emergency command center on the second floor and secluded himself in his office upstairs.

When the military helicopters tried again the following day, Hasegawa, Chuo Construction’s chief, sat glued to his television like much of Japan. After watching a spray of water drift aimlessly toward the nuclear plant, he knew that every minute mattered.

The businessman contacted a local politician, Eikei Suzuki, who had contacts in Tokyo, and asked him to offer Chuo Construction’s machinery for immediate use. It was early afternoon on March 17, just two days after radiation levels skyrocketed, and Japan teetered on the edge of a full-scale nuclear catastrophe.

Suzuki, who at the time was running for governor of Mie prefecture against the ruling party, got in touch with the Ministry of Economy, Trade and Industry in Tokyo and passed on Chuo Construction’s offer. Suzuki used to work at the ministry, a big promoter of nuclear power and also the industry’s regulator. Later the same day, the nuclear safety agency, which is under the ministry, called Chuo Construction: “Please wait awhile for a call from Tokyo Electric.”

While Hasegawa waited, military fire trucks and police water cannons were called in to squirt water from a distance. They sometimes hit their target but released so much water that the crippled nuclear facility was soon awash with contaminated liquid.

Only last week did Tokyo acknowledge that radioactive material released in these early days made the disaster a level-7 event on an international scale, putting it on a par with Chernobyl. And it took until Sunday for Tepco to admit that cooling systems crippled by the tsunami were beyond repair and will have to be replaced. This and other work to halt radioactive emissions and bring the Fukushima Daiichi facility to a stable state will last six to nine months, the company announced.

Three full days after his initial offer, Hasegawa received a late-night call from Tepco asking him to send his machines as soon as possible. He dispatched them the same night. Tepco, however, then decided it would wait for the arrival of similar devices from elsewhere.

Noriyuki Shikata, deputy cabinet spokesman, confirmed that Chuo Construction offered its machinery on March 17 and said the offer was passed on to Tepco the same day. “Due to the situation,” he added, “some loss of time” might have occurred, but this was because of “operational reasons” and the confusion attending Japan’s gravest crisis since World War II.

A Tepco spokesman, Yoshimi Hitosugi, declined to comment on the utility’s dealings with Chuo Construction. He said German- and Chinese-made pump trucks are now in use at the Daiichi plant but added that “it is extremely difficult to confirm the process of how decisions for each individual activity were made on the ground.”

Concrete pump machines, said Hidehiko Nishiyama, deputy head of Japan’s nuclear safety agency, are “more precise” than the helicopters and fire hoses that were initially deployed. He said the concrete pumps had been used “as soon as possible after they were offered.” Asked about Tepco’s delay in responding to Chuo Construction, he replied: “It is a big company.”

Stops and starts

The government, for its part, moved more swiftly to embrace the idea of using concrete pumps, though not those offered by Hasegawa. A day after the construction boss first made his suggestion, a deputy chief cabinet secretary met with the local boss of Putzmeister, a German company that manufactured the two machines owned by Chuo Construction.

Putzmeister had no experience in cooling overheated fuel rods, but one of its machines had been used in a 1986 operation to seal the doomed reactor at Chernobyl. Hiroshi Suzuki, Putzmeister’s Japan chief, took along a model of a truck-mounted concrete pump and explained that such devices could perhaps be used to fire water into the nuclear plant.

“They reacted quickly,” recalled Suzuki, who was asked whether his company could divert a pump truck then en route from Germany to Vietnam via Japan for use at the Daiichi plant. On March 20, the pump started moving toward Fukushima prefecture from Yokohama Port near Tokyo, but trouble with the machinery brought the truck to a stop.

At 10 p.m. the same day, Tepco finally called Hasegawa and asked him to send his own machines: “We need your help now!” Hasegawa recalls being told. His two pump vehicles set off on a 320-mile journey and, the following morning, reached a Tepco facility in Onahama, about 30 miles south of Fukushima Daiichi. Instead of carrying on to the nuclear plant, however, they were told to wait.

There had been a change of plan: The machine originally destined for Vietnam had been repaired and was back on the road. It started working at the nuclear plant on March 22. A second machine, also manufactured by Putzmeister, arrived from central Japan a few days later.

Still waiting

In the weeks since, Tepco, with help from the Japanese government and Putzmeister, has scoured the world for concrete pump trucks. Chuo Construction’s machines, though the first to arrive in the vicinity of the nuclear plant, sat waiting.

Hasegawa, Chuo Construction’s boss, takes some satisfaction from the fact that his idea, if not his machinery, has become a key part of emergency cooling efforts at the Daiichi plant. But he says he remains mystified by the holdup. One explanation, he says, might be that the government and Tepco “wanted to sort out this problem by themselves.”