Workplace Health and Safety Queensland has issued a safety alert after several accidents in which winch type (wind up) signs - commonly used in schools - have suddenly dropped, causing serious head injuries and hand lacerations. WHS has recommended the winch signs be lowered and removed from service until they've been upgraded with a new interlock offset handle system. The manufacturer, Spaceage Sign Systems of Caloundra, is in the final stages of designing and testing a safety upgrade to the system after a flood of requests from customers.
“The purpose of this safety alert is to highlight the risk of winch type (wind up) sign failure and risk control measures to help avoid further incidents,” says a Safety Alert notice posted on the Queensland Government’s Workplace Health and Safety website.
“This alert applies to winch type signs supplied by SpaceAge Signs and supersedes the alert released in 2014. The principles in this alert may apply to other brands of winch type signs.”
 |
| (LEFT - photo #1): Sign with an offset winch and upgraded safety gear (similar to the unit involved in the June 2019 incident).
(RIGHT - photo #2): Older type unit (not upgraded) with the winch attached directly to the post (Note: sign removed from cross bar). |
There have been two incidents in 2019 at schools in Queensland, says WHS QLD. In May, the winch was attached directly to the support post and the sign was being winched down when it suddenly dropped, with the winch wire rope running off the winch drum. The user was able to partially move out of the way but suffered hand lacerations from the falling sign.
The second incident in June involved a sign that had been upgraded with a revised braking system and an offset winch handle. It is understood that the sign was at full height and dropped suddenly with no warning - and with no one operating the sign. However, an eight-year-old child was standing near the sign. The sign dropped rapidly and stopped with such force that the rivets holding the sign to its frame were sheared off.
“Both incidents had the potential for serious or fatal injuries as the upper part of the signs can weigh in excess of 70 kilograms,” says the safety alert. “In addition to these latest two incidents, there have been a number of incidents in Queensland where wind up signs have dropped. Two of these incidents resulted in serious head injuries.”
Contributing factors
In the two 2019 incidents, the winch wire rope did not break and the safety gear that is intended to arrest the falling sign did not operate. It appears that in both incidents the sign dropped due to the clutch slipping (the winch mechanism includes an enclosed clutch assembly). The safety gear failed to operate, possibly because the wire rope remained intact and some tension remained on the rope.
In previous incidents, the older type safety gear failed to operate when the wire rope has broken.
Prior to the latest two incidents it was understood that retrofitting the signs with an upgraded version of safety gear would arrest the sign’s fall in all situations. However, clutch failure can also cause the signs to drop, the safety notice warned.
 |
|
'Very busy couple of months ahead':
|
The company that manufactures the signs, Spaceage Sign Systems of Caloundra West on the Sunshine Coast, says upgrades to the winch system should be available from next week.
“The recent incidents involved customers who had not followed through on the maintenance and service recommendations, which has resulted in all of the signs now needing to be modified again,” Janelle Royal, owner/director of Spaceage Sign Systems, told Wide Format Online.
"Most of our customers have done the right thing and have had all the upgrades and maintenance servicing. Some of these signs have been around for a long time, close to 20 years. They’re mechanical signs, there are wire cables, there’s rollers, and just like a car, they need to be serviced and maintained. We recommend that they’re serviced annually. Back in 2013/14 there was an upgrade to make them safer but some people never got the upgrade.
“What’s happened recently is there was one school that had a really old sign that had never received any of the upgrades and had not been serviced and maintained. Another recent incident involved a customer that did get the earlier upgrade but never had the sign serviced. Because of those two incidents, WHS want another modification on the sign - a winch interlock, placed over the winch. They sent out the alert and actually didn’t give us time to get everything in place. So we’ve had to design the upgrade, take it through testing, get it certified by an engineer and we’re in the final stages of getting that part ready now.
“We’ve contacted our customers, given them a quote for the modification, and we will then go out and complete the upgrade, service the sign and make a report. They will get a letter of certification and an updated service manual with instructions on how to use the new winch interlock.”
Royal says the company has been inundated with customer inquiries since the WHS alert was issued. “Just over the last week, close to 70 of our customers have gotten back to us to book in the upgrade. The signs are made here on site, they’re our signs and there are hundreds of them. We’re booking in everyone and then we’ll be heading out to install the modifications. We should be ready to go by mid-next week. It’s going to be a very busy couple of months ahead.”
Customers seeking the upgrade should contact Spaceage Sign Systems. New signs sold by the company will all have the upgrade.
WHS Queensland said: "In view of the number of incidents, it is strongly advised that winch type signs are lowered and removed from service unless:
The signs are upgraded and fitted with an offset handle (i.e. as shown in Photograph #1).
Engineering design certification has been carried out for the winch and safety gear.
A competent person:
- carries out a safety inspection on the sign
- provides a signed statement that the sign is safe to operate
- states when a re-inspection of the sign is required.
WSH Note:
On signs with the winch attached directly to the post, the raised sign should be carefully lowered with the operator’s body away from the potential fall zone of the sign.
While an offset winch means that the person raising and lowering a sign is out of the potential fall zone - signs can drop without warning and there is a risk to bystanders.
Warning labels that indicate people are not to stand under signs may be ineffective for children who ignore the warnings or may not understand that a sign may drop.
In the case of school children and members of the public, exclusion zones can only be relied on when people are physically prevented from entering a high-risk area.
The winching and braking mechanism on winch type signs is relatively complex and only highly skilled and trained personnel should carry out the safety inspection. Basic ongoing inspection and maintenance can be carried out by others so long as the manufacturer’s written instructions are followed.
While a competent person could potentially carry out a quantifiable slip test on the clutch assembly and then certify the sign, the safer alternative is for signs to be modified so that the raised sign does not rely on clutch friction but on a positive locking device (e.g. a pin or pawl that can be seen physically engaged).
Any sign upgrades should preferably be in accordance with the instructions of the sign supplier. Irrespective of whether the sign is modified by the sign supplier or another competent person, the design modification should be certified by a Registered Professional Engineer of Queensland. Certification only applies to the actual design. If the upgrade to the sign complies with the engineer’s instructions, there is no need for an engineer to inspect and certify every upgraded sign.
Sign operation
People operating signs are to be familiar with all the safe operating requirements and hazards associated with the sign.
Do not allow children or students to raise or lower the signs.
Do not use power tools to raise and lower the signs - as the winching mechanism will be damaged.
