A new luffer, better than the old luffer?29 December 2015
New York’s tightly packed and quickly built skyscrapers, busy streets, patchy electricity, and maze of subways combine to make lifting in city uniquely challenging and highly regulated. As the NYC Department of Buildings seeks to restrict the use of older cranes, the diesel luffers that dominate the city’s skyline face new competition. Will North reports.
The city of New York is one of the most challenging places in the world in which to use tower cranes. It is cramped, particularly in Manhattan, with very little room to set up or use a crane. It is busy, with millions of people passing job sites or working alongside them and hundreds of miles of subways passing below them. It is demanding, with the world's most demanding clients asking architects to design tall, awe-inspiring buildings. And it is expensive, with a unionised construction labour force demanding wages that reflect their skills, and high costs for road closures and delays.
That has come to mean that the city's tower crane industry has for decades been dominated by some of the world's fastest and strongest diesel luffers. Able to quickly carry concrete buckets hundreds of feet in the air, or to place the huge steel fabrications for soaring spaces, these cranes were the only choice for many of the most important projects in the city.
In 2008, two multiple fatality accidents in short succession pushed the crane industry into the public eye, and prompted a major revision of regulations. The city of New York for decades had operated a three-stage process of type approval, crane registration, and project engineering for work in the city.
After these accidents, and others, the city's Department of Buildings (DOB) set about revising these regulations, preventing the use of some established cranes, and encouraging new manufacturers to present their cranes to users.
James Lomma supplies more luffers in New York than anyone else, both diesels from Favelle Favco and electric cranes from Manitowoc Potain. Both crane types, he says, have their place, but on the biggest jobs, the dominance of diesels is clear.
"It's because of the high speed. You're going up 1,000ft. You're pouring concrete, you can't go up slow or the concrete will set in the bucket. It's a labour intensive job, and time is money. It's all about line speed. The Favelle Favco can pick up a whole trailer load of steel with single part line.
"The concrete buckets are only 15,000lb, but the Favelle Favco 760 will pick up 55,000lb single line, and then we have the 1280 that's good for 150USt at 50ft." That's enough power to place huge fabricated steel structures that form the skeleton of some of the world's most iconic buildings.
Jim Upton is Lomma's salesman in New York, working for him for more than 20 years. He says, "The Favelle Favco 440s are the crane of choice for concrete, and the 760s are the crane of choice for steel erection. People have tried to use electric cranes, and the Favco's give them far greater performance.
"A diesel crane, by design, has the ability to multifunction simultaneously. You can boom up, line up, and slew simultaneously." Matching that ability is still a challenge for electric cranes, although manufacturers are today developing ways to do the same.
Upton continues, "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 decades, one of the most popular cranes for the biggest jobs was the TG1900, based on a Favelle Favco design, but updated in the early 1980s by FMC, the then owner of Link- Belt. When Sumitomo bought Link- Belt in the late 80s, it sold the tower crane business to a local crane owner, who had ambitious plans to build the business, but struggled to bring them to fruition. Many crane owners, however, continued to use the cranes, which worked on jobs including the original World Trade Center.
The TG1900s were upgraded by the local industry, with Michael Schiavoni of Federated Crane playing a leading role. Schiavoni and his engineers designed an external sliding system that allows the base of a tower crane to be moved up the outside of a building during construction, and a steel basket system that supports the crane's base in a concrete building, without additional reinforcement. Most importantly, perhaps, they developed a new winch pack for the TG1900s, using modern hydraulic systems to create a new crane, nicknamed by many as the Super TG.
The Weiss family have been building skyscrapers in New York since the 1920s, and supplying cranes for 75 years. Paul Weiss established steel erectors AJ McNulty in 1925, with the eponymous Mr McNulty, and crane business Cranes Inc in 1940. His son, Lawrence, took over the business in the 1970s. Today, Larry's son, Robert, works alongside him managing both businesses, and plays a leading role representing the industry's interests to federal and New York regulators.
Rob Weiss explains the work Federated did on the TG1900s: "Mike had structural engineers and mechanical engineers work with the TG, and create the 'Super TG'. They took out the entire engine and winch pack of the 1900 and replaced it with a completely new all-hydraulic driven system. It was a very expensive upgrade, probably a half a million dollars. There was no change in the load charts, they were the same, but you were now dealing with all modern hydraulic winches and modern engines."
His father, Larry Weiss, explains, "High rise concrete needs, not necessarily the strongest cranes, but the fastest cranes, to get the concrete buckets up and down. Mike's upgrade of the winch pack was really very effective for that."
There were, at one point, perhaps 35 of the TG1900s working in New York. However, after accidents involving older cranes, and with no manufacturer recognised as able to support them fully by the city, 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
To understand the mechanism by which the TG1900s were effectively banned, it's necessary to understand the regulation of cranes in New York. Cranes in the city are regulated in three main ways. Larry Shapiro is a professional engineer working in the city. As such, he is closely involved with much of this 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, are vital to the 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 how the city can say it needs a manufacturer to back the crane. After all, 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. It's not just that owners need new cranes to replace those TG1900s. It's that they need the tower sections for them to built 1,000ft high 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."
The irony is that in a flourishing market, these costs will be borne not by the crane industry, but by developers, and, ultimately, by residents of their buildings. Rob Weiss says, "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." Revised regulations
The DOB has been working with stakeholders across the sector to improve crane regulation. The department has been going through the RS19 crane regulations. The first phase, which had finished consultation and was moving to a draft when Cranes Today visited, looked at the role of crane manufacturers: essentially, at the prototype approval process.
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."
This last point, prompted by an incident during Hurricane Sandy, was a contentious one for many in the industry, but has now been accepted by manufacturers. Hogan says, "You can train your own staff, as long as they are factory trained. So, if you own a crane company, you could have your own person trained and factory-certified as the technician."
Osman adds, "It can be from a dealer, as long as they are certified by the manufacturer. Then their name can go on the application."
At the same time as blocking the use of older diesel cranes like the TG1900s, the DOB has worked to bring new options to the city'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.
"We have additionally had discussions about, and made changes to, the prototype requirements, to allow the manufacturer to supply the data that was previously given by the PE. Before, if a manufacturer wanted to bring a new model crane into the city, they would have to get a New York PE on board to go through the prototype procedures. Now we have made it so their own engineer can submit the certifications required, and we'll approve the prototype. The PE only steps in for the site notification.
"This allows the manufacturer to absorb the cost of getting the crane prototyped and reduces the amount of time necessary for the New York engineer to be involved, which reduces the cost of the project.
"We identified as many crane manufacturers as we could and sent out notices in 2013. We had Wolff, Favco, Liebherr, Jaso, and Manitowoc present their cranes."
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 crane manufacturers identify a significant obstacle to the adoption of electric luffers in the city: long delays in bringing electric power to job sites.
Tim Birrenbach is service manager for New York at Morrow, and has followed the development of Liebherr's new 710 HC-L electric luffer from its first stages.
He explains the problem: "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."
At the same time as the manufacturers are talking to ConEd, the DOB is bringing together crane owners, their customers, and the power company to improve 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."
Over recent months, the two German crane manufacturers have both brought electric luffers in the 700tm class to Manhattan. Wolff has a 700B working on the World Trade Centre Tower 3, and Liebherr has a 710 HC-L on the new extension to MoMA, the Museum of Modern Art. Both companies developed and explained the benefits of their cranes to meet the demands of the market. Schiefer says, "We'd been in the US for decades, and then before I bought the company, had pulled out.
We started discussions with the DOB two years ago, when they said they wanted to have safer cranes in the city. At that time, I made a commitment, we're going to set up shop in the New York area, we'll be there as a manufacturer to back up and support the partners locally. "Some of our guys came from Germany and relocated here for a while to work on some projects. We've been working very closely with the DOB to get the cranes certified and approved for the city. And now we're here to support the customers. "When we started holding discussions for New York we talked to various people and tried to present our cranes, and line speed, line speed, line speed was the requirement. We looked into that and found out, first of all, you're not just talking line speed up, you have to look at the full cycle.
That's where the advantage comes in of a frequency controlled electric drive, because with an empty hook we can just go seamlessly at full speed, without having to change gear. It's not a diesel that has to ramp up first. It's just, you press a button, and off you go. "Keeping that in mind, we took that away and came up with the high speed winches. However, still if you look at what we need in terms of electric power in terms of what these diesels need, our engines still are very small, very efficient. The diesel engines are huge beasts. If we were to get anywhere close, installing that electric power, these cranes would be flying.
With diesel engines, we're talking 400, 500, 600hp. We have 132kW units. That's half, or a third, of the power, but still we can meet the speed and capacity." Morrow's Birrenbach says, "With the 710s, Liebherr and Morrow are really making an effort to get their market share in New York. With the 710, the marketing engineer, came out here two or three years ago, and we went to couple of jobsites and listened to the customers about what they want, to work out what they can implement. "We went to Biberach, and saw the crane in prototype. Liebherr's engineers asked us what we needed. Just simple things like positioning of platforms, the ability to put the cab on either side. Liebherr listens to those ideas. "This is the biggest luffer they've built.
This is leaps and bounds above anything they've had in the past. There's a lot of innovation in it. "They've focused on making the crane road legal when you're trucking it to the jobsite, there's no wide loads anymore. You can just put it on anything. They've kept everything light, so everything can be under 38,000lb. The entire crane comes in on containers or fitted inside the tower for shipping. It will all fit on a flatbed."