Safety Alert - BMU's - Suspended Scaffold Cradles

Failed bolt connecting the winch and the cradle.

BUILDING MAINTENANCE UNITS AND SUSPENDED SCAFFOLD CRADLES - Safety Alert | 06/11/2015 - This safety alert reminds owners and users of building maintenance units (BMUs) and suspended scaffolds of the need for ongoing inspection of critical components.

BACKGROUND: Two workers were seriously injured in October 2015 when the BMU cradle they were working in fell 10 storeys onto an awning below.

Initial investigations indicate the cause of the collapse was a failure of the connection between the winch and the cradle. This connection used a single bolt, loaded primarily in tension, at each of the two winches. It is believed one of these bolts failed, causing a sudden transfer of load to the bolt at the other end which then also failed.

The bolts are hidden within the connection and cannot be inspected without the connection being disassembled. Inspections revealed that both bolts show signs of significant fatigue cracking which would have weakened the bolts, resulting eventually in the sudden failure without obvious external warning signs.

In a similar incident in 2009 the failure of a simpler connection on a suspended scaffold cradle was also due to undetected fatigue cracks. It resulted in the death of one worker and serious injury to another.

Suspended scaffold connection bracket failure showing fatigue cracks.

ACTION REQUIRED

BMU and suspended scaffold cradle owners must:

• identify critical components in BMUs or scaffold cradles – eg where failure of a component would risk the safety of anyone in the vicinity of the BMU or suspended scaffold
• assess whether the current inspection and maintenance program adequately deals with these critical components, especially any components that need disassembly to inspect
• upgrade the inspection and maintenance program if necessary
• include non-destructive testing or regular replacement of components as part of the program where visual inspection alone is not adequate to detect potential developing defects, such as fatigue cracks
• carry out a major inspection on any BMU that is over 10 years old and has not yet had a major inspection
• carry out a major inspection on any BMU that has had a major inspection:

but is overdue for its next recommended major inspection, or
five years after the last major inspection where no recommendation was given.

Preliminary findings of window cleaners’ fall in October released: A Sydney window cleaner was injured after falling approximately four floors onto a balcony while cleaning windows on a hotel at Gloucester Street in The Rocks. The window cleaner, who was using rope-style window cleaning equipment, is reported to have suffered leg injuries in the fall.

SafeWork NSW is investigating the incident which comes as they release the preliminary findings of their investigation into an incident where two men fell approximately 10 storeys from a Sydney CBD building on Tuesday, 20 October. The men, who were harnessed, were cleaning windows on a 12 storey building on the corner of Pitt and Bridge Street in the city when the window cleaning cradle that they were working in suddenly fell to the awning below.

SafeWork NSW commenced an investigation into the incident which included sending the window cleaning cradle, known as a building maintenance unit, to SafeWork NSW’s TestSafe facility at Londonderry for testing and analysis.

The initial findings of the investigation indicate that the cause of the collapse was a failure of the connection between the winch and the cradle. The connection used a single bolt, loaded primarily in tension, at each of the two winches. It is believed one of the bolts failed, causing a sudden transfer of the load to the bolt at the other end, which then also failed. The bolts, which are hidden within the connection, cannot be inspected without the connection being disassembled.

Inspections revealed that both bolts showed signs of significant fatigue-related cracking which would have weakened them, resulting eventually in the sudden failure which occurred without warning.

In response to the findings, SafeWork NSW will undertake an awareness program and verification activities in early 2016 on buildings where Building Maintenance Units and Industrial Rope Access are used. SafeWork NSW Executive Director, Peter Dunphy urged all owners and users of building maintenance units and suspended scaffolds to inspect their equipment in the lead up to the verification visits.

“Operators should undertake regular inspections of building maintenance units and suspended scaffolds so that defects such as fatigue cracks are identified,” Mr Dunphy said. “They should also consider whether their current inspection and maintenance programs are adequate to prevent equipment failure in the future.

“A similar incident occurred in 2009 due to undetected fatigue cracks on a suspended scaffold which resulted in the death of one worker and serious injuries to another. “Fortunately, although the workers were seriously injured, they both survived, but the result could have been very different.”

SafeWork NSW has published a safety alert with guidance for owners and users of building maintenance units and suspended scaffolds on how to prevent similar incidents. Operators seeking further information on building maintenance units should refer to the Australian Standard.

An Equipment Failure & New Window Cleaning Record?

George Lynn is going for a Guinness world record for cleaning windows.

Window record open: Most 63-year-olds with rheumatoid arthritis would be more than happy to put their feet up and relax in their retirement days. George Lynn, however, is not your average 63-year-old.

The Mirrabooka pensioner has now travelled across Australia four times in an effort to establish a Guinness world record for the most windows washed in a year. The window-washing bug first bit him in 1988, when he stopped over in Abu Dhabi with no local currency. “I was in the airport with no local currency, and I found a café owner that spoke English, and I asked him if he could make me a cup of tea if I washed his windows,” he said. “He told me he’d make me a cup of tea and also give me five dollars – and I’ve been washing windows ever since.”

Despite his severe arthritis, George is aiming to wash one million windows between Australia Day 2012 and Australia Day 2013. “I’ve already done 4000 windows so far, so I am going to have a decent crack at it,” he said. “In four attempts I’ve not managed to get upwards of one million – but I’m hoping my luck will change this year. “I’ve got all the documentation I need, I just need to get the windows done.”

George charges $2 per window, with one third going to the RFDS, one third going to the Cancer Council and one third to himself. “I can assure you I’m not making a quid out of it. It’s just enough to support my pension and keep me washing windows.”

Crane malfunctioned atop San Francisco high rise: A crane accident happened in the Financial District Sunday around 2:30 p.m. A crane came loose dangled off a high rise at the corner of California and Kearny streets. About five tons of mechanical equipment inside a container dangled off the side of the Bank of America building, near the top, right over Kearney Street. Workers told ABC7 they were installing new window washing gear on the roof of the Bank of America building and have been doing it for the past three days, but they said the load that got stuck was the heaviest load they've lifted so far. The weight proved to be too much for the crane. The container weighs 11,000 pounds and it was dangling over 500 feet in the air. "It contains two spools of wire weighing about 11,000 pounds and the winch snapped, so now the only way they can get it up there is they're going to have to hand crank it. It's about 100 feet they have to bring it up. It's going to take about 3-3.5 hours. There's no danger right now. We've got everything locked down, we've got traffic and pedestrians out of the area. We've got officers at all the corners to make sure that nobody gets in there," said San Francisco Police Sgt. Joe Fisher. There were two men cranking the container up and around 6 p.m. they were moving it at a rate of 20 feet in an hour. This caused traffic jams all over the area and Chinatown.