Lifting in New York poses a unique challenge overseen by high levels of regulations. Quickly-built and tightly-spaced skyscrapers combining with busy streets, problems with electricity supply, and mazes of subways. Now NYC Department of Buildings plans to prohibit the use of older cranes. Will North reports.
For tower crane users, the city of New York provides one of the most challenging arenas in the world. There is little space, particularly in Manhattan, and so limited room to set up or use a crane. There are millions of people who pass or work by job sites, and a huge network of subways passing below them. It is home to demanding clients, who work with architects to plan tall, awe-inspiring buildings. And working in the city is expensive, with a unionised construction labour force charging rates that reflect their skills, and high charges for road closures or subsequent delays.
The result of this atmosphere is that the city has long been dominated by the fastest and strongest diesel luffer tower cranes. Their ability to quickly manoeuvre concrete buckets high in the air, or to place the huge steel fabrications on tall structures, made them the only choice for many of the key projects in the city.
In 2008, two accidents that caused multiple fatalities occurred in short succession, putting the crane industry in the public eye and resulting in a major revision of regulations.
The city had for decades operated a three-stage process involving type approval, crane registration, and project engineering. After the accidents of 2008, and others, the city’s Department of Buildings (DOB) revised the regulations, which prohibited the use of some established cranes, and encouraged new manufacturers to put forward alternative solutions.
James Lomma is the leading supplier of luffers in New York, providing diesels from Favelle Favco and electric cranes from Manitowoc Potain. Both types have their place, he says, but on the biggest jobs there is a clear preference for diesels, because of the high operating speeds they offer.
Jim Upton, Lomma’s salesman in New York, adds, “A diesel crane, by design, also has the ability to multifunction simultaneously. You can boom up, line up, and slew simultaneously.
“The labour rate in New York City, and the time it takes from start to finish on some of these buildings, you could be talking months difference. That’s a lot of money. For most labourers in the city, whether it’s ironworkers or concrete workers, with their benefits packages, you’re talking over $100 an hour.”
For many years, one of the leading cranes for the largest jobs was the TG1900. At one stage, there were around 35 of the TG1900s working in the city. But accidents involving older cranes, and a lack of a recognised manufacturer able to support them fully in the region, the DOB took steps to prevent their use. Rob Weiss says, “It created a real void when these cranes left, that has changed the landscape.”
Changing the landscape
The crane regulations in New York City that effectively banned the TG1900s operate in three main ways. Larry Shapiro is a professional engineer working in New York, and so closely involved with much of the process. He explains, “Any crane that comes into the city has to be an approved model, so there’s an approval process. It has to be registered. And each on site installation has to be engineered and approved. That’s designing a crane installation, and getting it approved by various city agencies.” Professional engineers (or PEs), recognised by the city, play a key role in type approval and installation steps.
Thomas Hogan is deputy commissioner for enforcement at the DOB. He says, “Currently there is no strict age limit on the age of cranes in New York. What we have found is that there are problems with certain models, some of them based on issues related to age. For example, for the TG1900, there is no original equipment manufacturer anymore available for parts. Our building code requires you to use original manufacturers’ parts in the crane if you need to do a repair, and they were not supported. Based on that, and some incidents related to the TG1900s, we cease-used them.
“A cease use order removes the city’s prototype approval, and says you cannot use that crane. The city has a requirement that every year you file for approval for any crane you use in the city, and that’s compared against the list of prototype approved cranes. Once the prototype approval is in, you file a crane notice, that you’re going to use a crane in a particular location. If we find a situation where there is a failure linked to a particular type of crane, we revoke the prototype approval, and will not approve crane notices for that type of crane.”
Crane owners have questioned the city’s line that a manufacturer is required to back the crane, as many parts can be replaced to the same standard by other engineers. Larry Weiss says, “There’s nothing in the law or regulations that says there has to be a manufacturer standing behind the crane, yet they decided on that basis not to allow these cranes in the city.”
Rob Weiss adds, “I’m very afraid of an age limitation coming in, when all the industry, all the scientific studies, show it is use, not age that matters. You’re taking a valid product, and throwing it out the window.”
The DOB’s Cranes and Derricks Unit is headed up by Ashraf Osman. He says, “We have in RS19 [the city regulations covering cranes] a requirement that any repair has to make it to at least the original safety factor, as per the manufacturer’s specification. If an engineer demonstrates a repair will reach this safety factor, it will be allowed, as long as we don’t have specific issues.
“But with the TG cranes, as deputy commissioner Hogan mentioned, we had other issues with the design itself. So the original prototype approval of the crane itself was revoked. We’d had issues with failed hydraulic motors, the main hoist system was not enough, the motor failed, and there was a reduction in the horsepower. So, the hydraulic system design itself didn’t have any failsafe. This was one of the main reasons we revoked the prototype.
“A TG1500 on the Freedom Tower, installed as a slider crane, dropped the load. Luckily, the operator was able to stop it, 100ft above the ground. It was freefalling, and then stopped at the last minute. And then a few weeks after, on a TG1900, the load dropped, and came down on a truck below.”
The result, as Rob Weiss says, is a void in the market. The issue is not just that new cranes are required to replace the TG1900s, but that new tower sections are also needed to build skyscrapers.
Larry Weiss says, “When tower cranes are in demand, there may be a shortage of tower sections for external climbing cranes. All of these new high rises, going 1,000 or 1,500ft, where they want to go external, there will be a shortage of tower sections, and that will be very expensive.”
Rob Weiss adds, “With the TGs, there were thousands of feet of tower sections everyone owned already. The biggest expense in buying the crane, from the turntable up you can buy it relatively reasonably, but if you want a thousand feet of tower, you start adding millions to the price of the crane.”
“We don’t have a stock of these sections. We’re all starting from scratch. And that’s a very tough position, and we have to add it to the cost. We’re lucky we’ve been busy, and with the banning of the TGs, the rental rates have gone up. The ban gave a huge advantage to [Lomma’s] New York Crane, as they had the Favcos ready, and could push their rates up.
“And then Morrow were able to come in on the coattails of that. We’ve seen the rental rates of this equipment go up to where they should be.”
The DOB has been working with the sector to improve crane regulation. Shapiro says, “The approval process has evolved. In the old days, we would replicate the structural analysis the manufacturer did, to prove the crane can work within its load chart, and then we would submit an affidavit, certifying that the crane complied to various requirements. They’ve largely accepted manufacturers submitting affidavits, verifying they comply to various standards.”
Deputy commissioner Hogan says, “We’re not stopping any manufacturer submitting an application to us. As long as they are in compliance with a certain standard, and with ISO. We accept the American standard for tower cranes, ASME B30.3, and we’ve adopted acceptance of the European standard, EN 14439.
“There’s no need any more for the professional engineer to [certify the design for prototype approval] for tower cranes. That item we’ve already clarified. As long as an engineer from the manufacturer can look at if it meets our wind design criteria, and our building codes. It’s up to the manufacturer if they will review it, or a professional engineer will. They give us the affidavit of compliance from the manufacturer, the ISO certification, the load charts, they confirm technical and service person information, and show that this person is available in four hours as needed.”
While blocking the use of older diesel cranes, the DOB has worked to bring new options to New York’s crane market.
Hogan says, “Over the last two years, we invited manufacturers to meet with the department and the industry in New York, so they could show the newer crane technologies that have been introduced. We arranged forums for this.”
Cranes Today met with two of those manufacturers or their representatives in New York: Wolff, and its dealer, Empire; and, Morrow, dealer of Liebherr tower cranes in the USA.
Both manufacturers identified a significant issue impeding the potential adoption of electric luffers in the city: the long delays in electric power reaching job sites.
Tim Birrenbach is service manager for New York at Morrow, and has been following the development of Liebherr’s new 710 HC-L electric luffer from its first stages.
He says: “It’s a two year lead time to get local power supplier ConEd to come in, to supply the three phase 480v needed. In New York, it’s on 208v, so you need to get a transformer in at the base of the crane to step it up. Or you need to bring in a diesel generator.”
Jason McKenzie, of Wolffkran’s dealer Empire, agrees, “ConEd’s probably been the biggest opponent to tower cranes in the city. To this day, they are still a bit slow, even providing temporary power to a job site, let alone maximum power needed.”
Peter Schiefer, CEO of Wolffkran, adds, “The electric requirement, the power requirement, of one of our cranes, is minimal compared to what these sites need later on for, say, the air conditioning, just for running the whole building. There are no greenfield sites, they are all brownfield, they all have the power, they all have had power. They have more power than we’d ever need for an electric tower crane. So, I think the issue is a different one, more that they want to protect the whole grid from faulty or insufficient equipment being connected and causing a problem. As a company, we want to dive more into it, because we think we can maybe help on that.
“With new variable frequency drives, we’re not sending these peaks into the grid all the time. It’s a very moderate power consumption, and I think the way our electronics are designed, we don’t cause many problems for the grid.”
While manufacturers are talking to ConEd, the DOB is opening communications between crane owners, their customers, and the power company, with the aim of improving planning. Hogan says: “The main issue with ConEd is their ability to deliver that level of electric power. The majority of places where construction is delayed, are older neighbourhoods with the older infrastructure. If you need high voltage supply in midtown Manhattan, you don’t have a two-year wait. If you want it in Chinatown, which was built in the 1800s, they need to dig up the street, for a number of miles, to get the electric service to it.
“One of the things we’ve raised, when developers are finishing the plans, they pretty much know what type of crane they are going to use down the road. And so our recommendation has been that as soon as you know that you have a crane that’ll need that much electricity, you give the plan to ConEd. You can control the availability of power. You just need to do the notification early enough.”