NEW YORK (AP) – It takes a lot of paper to raise a crane in New York City these days.

On top of maintenance records and operator certification tests, engineers have to sign off before cranes are raised or dismantled. The city also requires documents that prove a safety meeting was held before work begins.

It may seem like a lot to ask for, but New York is seeking to become a national example after two deadly crane collapses in Manhattan killed nine people this year.

This year’s spate of deadly accidents in New York and other U.S. cities, including Houston, Miami and Las Vegas, triggered the federal government in September to propose updated crane regulations for the first time in 40 years.

But New York has introduced more stringent rules governing constructions in addition to those required by the federal government, including laws that require training for tower crane workers, limit the use of slings that hold loads, and overhaul licensing requirements for mobile crane operators.

“We have worked closely with industry officials to develop checks and balances that are making construction sites safer than ever before,” city Department of Buildings spokesman Kate Lindquist said. “There are thousands of construction sites in New York City that are managed without incident every day, and there is no reason why developers cannot build safely to avoid any preventable delays.”

But the city’s construction industry says the rules are difficult to follow, hard to enforce and often cause costly delays. Contractors say sites are often shut down for days or weeks for minor violations, like a missing piece of paperwork, and stopping work at a high-profile site can cost more $100,000 a day.

“In some respects, it’s already overkill,” said Louis Coletti, president of New York’s Building Trades Employers Association. “You’ve got new rules and regulations coming out every day.”

In midtown Manhattan, where a crane crashed into a town house on March 15 and killed seven people, a crane still hasn’t returned to the high-rise development site. A crane at the site of a May 30 collapse that killed two workers was not re-erected until September.

Work stopped at both sites for months, and the latter site was ordered to stop again a week ago because of a missing permit.

Coletti said contractors have received orders from multiple inspectors with conflicting interpretations of building codes, and finding an inspector to lift an order can be as challenging as fixing the violation.

Contractors are most up in arms over a requirement for engineers or manufacturers to certify plans to raise tower cranes. They say professionals would be unlikely to approve plans for work they can’t supervise.

Alfred G. Gerosa, executive director of the Cement League, whose members often contract out crane work, said in September that the rule could “shut down the entire tower crane industry in the city.”

Frank Bardonaro, president of a suburban Philadelphia crane rental company and head of the Specialized Carriers & Rigging Association’s crane safety task force, called New York’s rules “unenforceable.”

“Are you going to test every bolt, nut, bracing?” he asked.

The city maintains the regulations are standard across the construction industry and are necessary to ensure safety.