MRO Magazine

Strength In Numbers

Hidden in the bowls of the Pierre Elliott Trudeau International Airport in Montreal is a labyrinthine system of conveyors, chutes, pushers, sorters and tilt trays, powered by hundreds of motors and bo...


September 1, 2009
By Carroll McCormick

Hidden in the bowls of the Pierre Elliott Trudeau International Airport in Montreal is a labyrinthine system of conveyors, chutes, pushers, sorters and tilt trays, powered by hundreds of motors and bossed around by software that in turn makes split-second responses to endlessly-changing real-time data on sometimes thousands of pieces of baggage an hour.

Riding shotgun on this system is Axima Services, a Montreal-based technical management company. It took over the maintenance and servicing of the airport’s baggage handling system (BHS) in September 2005. The Trudeau airport (formerly Dorval International Airport) used to maintain the system in-house, but its growth, increased passenger throughput and an increasingly-complex BHS forced a review of maintenance practices. Airport operator Aroports de Montral (ADM) decided to get out of the BHS maintenance business and Axima won the maintenance contract.

“When you calculate everything, the maintenance budget has not gone up. Axima gets the latest technology and it is their responsibility to keep the staff training up to date. It does maintenance at many airports around the world. Going with an outsource service, we were gaining expertise,” explains Pierre-Paul Pharand, director, operations, ADM.

For example, the most recent belt conveyor ADM commissioned was in December 2005 under the guidance of the same Axima employee who was responsible for the building and start-up of the new bag room at the Athens International Airport in time for the 2004 Summer Olympics.

The Trudeau airport has three baggage handling systems. Two traditional belt-conveyor systems serve domestic and international traffic, and are considered as one in this article. The third system, commissioned in the summer of 2009 to serve trans-border (US-bound) traffic, is an entirely different creature and is not covered here.

The BHS, located under the main terminal, is fed via 135 ticket counters and seven bag drops. Dual, redundant conveyors between the ticket counters and the security room, where bags are scanned for explosives, provide backup in case of some BHS system failures. After passing through the security room, bags travel to a racetrack-shaped tilt tray system, which deliver bags to piers — airport-speak for the locations where handlers collect baggage on to carts and drive them to waiting aircraft.

That is the short version of the trip, but the delight and the devil are in the details: There are 1,600 pieces of equipment (70 different types) listed in the airport’s Maximo preventive maintenance software program. There are six kilometres of belt conveyors, and 980 motors sourced from SEW Canada that range from 3/4 hp to 3 hp, with the exception of one 5-hp motor.

Twelve beefy vertical sorters shunt baggage up or down to different parts of the BHS. There are also pushers, ram-like devices that punt bags from one conveyor to another running at a right angle to the first.

The tilt tray system is a 230-metre long conveyor, but with a difference: rather than being made of rubber belts, it consists of 212 wooden trays that look suspiciously like the business ends of those seats found in elementary schools. The conveyor goes ceaselessly round and round, the trays tipping baggage into chutes at the correct piers. Suspended from the ceiling, the tilt tray system is the highest-maintenance part of the BHS, requiring 160 hours per month of preventive maintenance (PM).

In all, the 15 maintenance staff, which includes electricians, mechanics, PLC programmers and IT technicians, handles about 100 work orders a month for the BHS.

The BHS is described as an electromechanical system with a high degree of automation, according to Pierre Loyer, director, Airport Group, Axima. “The equipment is simple and it is easy to maintain, but the system [software] on top of it is where the complexity lies: the automation and IT.”

Axima constantly strives to improve the performance of the mechanical system, which by one definition, is the rate at which it processes baggage. The design capacity of the BHS is 5,800 bags per hour. “We run a very intensive continuous improvement program so we can reduce our intervention with the system,” Loyer says. “We use Six Sigma on a daily basis.” (Six Sigma is a business management strategy aimed at improving processes and eliminating defects.)

“It is important to implement statistical measures for the system. At one merge, for example, we were having a lot of jams. The fact that we could measure how many [there were] gave us information that led us to realize that we could change the configuration of the merge.”

Every glitch, such as a jammed bag, automatically generates an event report, even though it may not affect the system. For example, while Magazine was on site, a bag was caught up by its baggage strap, which had snagged on the corner of a conveyor behind a check-in counter. Loyer quickly unhooked it, but commented that the snag had nonetheless been logged.

This snag would not have happened had the check-in agent put the bag and its dangling strap in a baggage tub, according to Loyer. In fact, he notes, humans in the system cause far more problems than any mechanical issues. “We can analyze the jams and go back to the airlines and train [their staff]. We ask airlines to let their personnel take an hour to tour the system and visually see the trouble that they can cause … a baggage strap can rip off a piece of belt.”

Axima keeps $600,000 worth of spare parts on hand. To ensure that the right parts are available, Axima has identified higher-risk parts of the system. “Our target is to always ID critical equipment and the critical parts. We analyze the risks, and the time to deliver parts,” Loyer explains. For example, there is a transformer that reduces a 600-volt feed to 480 volts for the tilt tray. Despite costing $15,000, Axima keeps a spare on hand: were it to fail, half of the BHS would go down. The transformer takes just 20 minutes to replace, but 14 weeks to order.

In a six-kilometre system, conveyor belt selection is a science. “Belt selection is a big, big thing. They are chosen for the right friction situations, or whether the belts decline or incline. Belts can last for years, but if you use the wrong belt in an area, you will get a lot of wear,” Loyer says.

Cleanliness is another challenge, especially in the winter, when the urea used to de-ice the aprons creates more dust than usual. The BHS has nine locations where bag tags are read with bar code readers. Each reader consists of 12 heads arranged in a circle around a gap between two belts. This 360-degree coverage allows tags to be read no matter what their orientation, but as any shopper knows, bar code readers sometimes are unable to read the data. Loyer attributes the readers’ 96% read rate to regular PM on the heads, with extra attention to cleaning them in the winter. Regular analysis of the quality the output of the bar code printers helps as well.

Axima answers to ADM for the performance of the BHS, but meetings with ADM and the airport’s tenant airlines are not just to discuss Axima’s report cards. “A committee of airline, ADM and Axima representatives meet once a month to discuss performance, operational issues and expansion possibilities. This is a steering and operational committee. We give reports on the service levels, system uptime, intervention time, read rates, etc,” Loyer says.

The committee was struck after the BHS became common-use — that is, when all 39 of the airlines at the facility began using the same BHS, as opposed to each having its own. The exchange of information and good communication ensures that everyone understands their roles in keeping this hidden but critical part of the commercial aviation supply chain functioning smoothly.

Montreal-based Carroll McCormick, an award-winning writer, is the senior contributing editor for Machinery & Equipment MRO.