Controlling the movements of trailers that arrive from all over the country, unloading them and then reloading them with the correct packages for next day delivery is at the heart of the company's operations.
"TNT's seven-day-a-week operations are centred on providing a maximum 24-hour delivery cycle for everything we handle. That means processing hundreds of thousands of individual packages from 65 regional offices every day," says systems support manager Mick Spragg. "We operate a hub system with all items being processed at four national sortation centres in Northampton, Lount in Leicestershire, Atherstone in Warwickshire and Kingsbury in Staffordshire. We also have two regional sortation sites at Basildon in Essex and Preston in Lancashire."
"Ten years ago, we operated just two main hubs at Northampton and Atherstone and employed a manual system to control all on-site trailer movements," Spragg explains. "It was based on a modified taxi dispatcher system, with individually allocated moves. However, as the volume of business grew with the opening of our Kingsbury facility, we looked to automate the process - subsequently developing our first general management system in conjunction with AEG. This interfaced with an updated dispatcher system, which relayed instructions by radio to the tugs used to position the trailers at the required bays on the side of the building."
The system delivered major benefits by eliminating the need for typed instructions. However, some niggling shortcomings soon became apparent, notably an unacceptably high number of data drop-outs over the network. This led Spragg and his colleagues to investigate the implementation of an RF based solution using more 'rugged' terminals mounted in the tug cabs.
"Again, the solution was good in theory," says Spragg. "But the terminals
available at the time were simply not robust enough to cope with the
conditions they were operating in. Vibration is the main issue. Most of our
tugs have rigid suspension and we found that components would literally be
shaken off the terminals' motherboards in just a few months. None of them
lasted for more than a year, but it wasn't a functionality problem - simply
a matter of finding terminals that were tough enough to withstand the
punishment they endured in service."
It was a problem that Dave Cantrill, TNT's plant and maintenance manager for
sortation systems was acutely aware of when he visited DLoG's stand at the
IMHX exhibition in 2004. Following a demonstration of the
recently-introduced MPC series of vehicle-mounted terminals, DLoG was
selected as one of four suppliers to provide hardware for a 12-month
extended evaluation programme at TNT's recently opened Lount site.
"Given our previous experiences, durability was certainly one of our key
evaluation criteria - as was vendor support," says Spragg. "Other important
factors included build quality, equipment cost, warranty and fitness for
"Right from day one, we were impressed by the support we received from DLoG
during the setup and installation phases of the test programme.
Subsequently, we found that its MPC units represented the most complete
package over the course of the 12 month programme."
As a result, an initial 25 MPC terminals were fitted to tugs at TNT's four
national sortation centres, with a further four units subsequently added to
the fleet as business levels continued to grow at each site.
"With three years service in vehicles that complete a move every 40 seconds
at peak periods, the decision to specify DLoG units has been entirely
vindicated," says Spragg. "The units have proved to be extremely reliable
during this period. The MPCs combine secure mobile computing power with
simple touch screen commands - all housed in a rugged, IP67 certified
From the tug drivers' point of view, operation could not be simpler.
Operators are automatically logged on to the system as soon as they switch
on the tug's ignition and required moves are issued from the central
management system directly to the onboard MPC terminal. Each move is broken
down into five categories: offered, accepted, POB (passenger on board -
reflecting the company's original taxi-based system), STC (soon to clear)
"We have recently extended the system's functionality to validate that
trailers are positioned correctly at the appropriate bay before considering
a move to be complete," notes Spragg. "Within a second of finishing a task,
the next move will be displayed on the terminal's screen, providing an
uninterrupted flow of work that enables tugs to complete up to 100 separate
trailer movements each during a shift."
The terminals run on Cisco wireless LANs at each site and reflect TNT's
drive for standardisation across all of its worldwide operations.
"It simplifies maintenance and enables direct substitution of hardware if a
unit does happen to go down," says Spragg. "Not that we've experienced any
real problems with the MPC equipment, or needed much support from DLoG since the units were installed. We confidently expect the terminals to achieve the
five-year target service life we've set for them. What's more, on the basis
of their performance to date, we have already specified two new DLoG IPC 7
units with 15-inch screens for static applications at our Kingsbury site.
We're also planning to add two more MPCs to the tug fleet in the near
"In a business where you are only as good as your last delivery, dependable
systems are central to the company's ongoing success. Consistent hardware
performance over a long service life not only builds confidence in the
equipment, it ultimately underpins our ability to exceed our own customers'
With that in mind, it should be no surprise to learn that DLoG hardware has
also been specified as an integral part of the preferred solution for TNT's
UK parcel management system as it is rolled out to other group operations