Unmanned Weighbridge Systems

Introduction
In recent years unmanned, or driver-operated, weighbridges have risen in popularity. When automatic weighticket printers were introduced, freeing the weighman from the lengthy task of hand-writing the tickets, many organisations combined the post with that of security officer. This is still quite common, but as the security aspects get more and more time-consuming in themselves, it can be difficult for the officer to allocate enough time to looking after the weighbridge as well.
Unmanned weighbridges dispense with the need for a person to be allocated to the operation of the weighbridge, full or part time. They allow the wagon drivers to become their own weighmen, whilst at the same time giving maximum security of information in spite of little or no driver training.
Rontec have wide experience in the specialised field of unmanned weighbridges.
Our equipment is chosen by some of the biggest weighbridges users in the country and has a proven track record of reliability and successful operation over a number of years
When to consider unmanned weighing
The unmanned option is suitable for almost any weighbridge application, but the greatest benefits are seen when repetitive runs are being made by wagons delivering or collecting materials. The initial cost of installing an unmanned system can be quickly repaid by savings on personnel and the speed and accuracy of the data that is automatically captured by the system. Obviously, the busier the weighbridge is, the greater the potential advantages are.
What is involved in choosing unmanned?

In law, the weighbridge operator is responsible for ensuring that the weights obtained from the weighbridge are correct.
In practice, this means that he has to check two things before taking a reading:
1. That the weighbridge is set to zero before the vehicle drives on to the platform; and
2. That the vehicle is correctly positioned on the platform.
The wagon driver will have no way of knowing whether or not the weighbridge is reading zero without stopping and getting down from his cab and so it is a requirement that the zeroing operation is done automatically. This is normally accomplished by having induction loops in the roadway about 5 metres before the platform - at both ends if the weighbridge is to be used in both directions. When the wagon passes over the loop, a signal is sent to the weighbridge control system and the digital weight indicator is zeroed automatically. If for any reason this does not happen, the driver is advised by the system and the weighing cannot proceed until the platform is emptied and the zeroing procedure repeated.
To make sure that the wagon is correctly positioned on the platform the weighbridge is fitted with either rising traffic barriers or infra-red beams across the ends of the platform. In this way the weighing can be prevented if the wagon is not properly placed on the weighbridge.
So, in addition to the usual weighbridge equipment an unmanned system at its simplest needs:

-zeroing devices embedded in the roadway

-traffic barriers or detection beams at the ends of the platform

-a computerised control system to operate the above and to prompt the driver

-an automatic ticket-issuing printer

-a keypad or colour touchscreen to allow the driver to tell the system about his journey
However, to get the best out of an unmanned system it is much better to go a step further. Only when automated driver input, data logging and full traffic handling are incorporated does an unmanned system really come into its own and start to pay back the investment put into it.
The traffic handling can be carried out by the Rontec control system that oversees the running of the weighbridge and a Personal Computer, in the weigh office or elsewhere, will log all the weighing details on to its hard disk.
The Rontec Datakey system
The Rontec Datakey System is a tried and tested means of getting the maximum amount of information from the driver and into the weighbridge control system quickly. It comprises a rugged plastic key in which is embedded an EEPROM chip that can hold hundreds of characters. The weighbridge control system can read the chip and, if required, write new data back on to it. All the driver has to do is to insert the key into a receptacle and turn it through 90 degrees. The display then guides the driver as to what is happening and asks him to remove the key when the operation is over.
Rontec will tailor the system to do what you want it to do. The key may hold nothing more than the wagon's registration number, allowing the weighbridge system to look up its tare weight, owner and other details; or it may hold a great deal more information that is read into the weighbridge control system's memory.
The Datakey has now told the system all it needs to know about the vehicle that has just arrived. Optionally, it may also have told it what product the wagon is carrying, where it has come from, who owns it and where it is going, along with any other information required by the system. Now the information from the weighbridge itself can be called for and added to the Datakey information to provide all the details known at this stage. The key will know whether this is a first or second weighing - the system may be set up to write a computer transaction record after the first weighing, to be completed automatically after the second one; or it may write this record only after both weighings have been done. In either case, a complete transaction record will be made after the second weighing and held on the hard disk of the PC, situated either in the weigh office or remotely.
RF Tag system (Alternative to Datakeys)
Non-contacting RF tags, which can be supplied in a variety of shapes such as key fob, credit card, etc., may be specified as an alternative to Datakeys. These tags hold a single and unique identifying code on them that cannot be changed, but is used to look up full details held on the computer. These would normally comprise registration number, stored tare weight (optional), operator name and address and any other data permanently associated with that vehicle.
The driver holds the tag against the face of the reader, which may be in the weigh cabin or outside on a pole so that it can be accessed without leaving the cab. Everything else is then automatic.
The Personal Computer

The PC provided with the system is a standard unit, which means that maintenance is greatly simplified.
No obscure additional cards or devices are required. In the unlikely event of computer failure, the original PC
can be exchanged for another similar one - even by the owner of the system.
The transaction file, in Microsoft Access database format, holds one record for every pair of weighings made.
The second weighing is automatically linked to the first weighing, using the registration or fleet number as a unique "key".
It is this file that forms the basis for the reports that can be produced by the computer. Rontec can provide a series of report formats to give printed details of business transacted in any form, whether customer, date or period based, or in any other configuration required. Alternatively, the data can be exported into a proprietary spreadsheet, such as Microsoft Excel.
Some of Rontec's larger customers have the PC linked by Modem to control centres or head offices, possibly hundreds of miles away from the weighbridge. This enables them to read the transaction file on the PC's hard disk at any time and to keep track of weighings being carried out right up to the moment of interrogation.
Some of Rontec's larger customers have the PC linked by Modem to control centres or head offices, possibly hundreds of miles away from the weighbridge. This enables them to read the transaction file on the PC's hard disk at any time and to keep track of weighings being carried out right up to the moment of interrogation.
The Rontec traffic control system
For busy weighbridges with a lot of vehicles to handle, Rontec can provide the answer to traffic congestion.
This can be particularly acute if the weighbridge is used in both directions, where there is often a risk of wagons meeting "head on" at the weighbridge. The whole idea of traffic control is frequently overlooked, yet it is in fact very important. It is useless to have a fast and efficient data collection system at the weighbridge if access to and from the platform is slowed down because of vehicle congestion.
Rontec's solution is to provide holding areas some distance from the platform itself. These are controlled by traffic barriers or lights, linked into the main weighbridge control system. By keeping track of vehicle flow the system is able to retain wagons at the holding areas until the weighbridge is clear and ready to accept them. If space on site is limited, the system can even bias the flow in such a way that wagons leaving are given priority over those arriving.
Conclusions
Whether or not to choose the unmanned option is an important decision. In terms of equipment it is of course considerably more expensive than a conventional weighbridge with an operator in attendance at all times. In terms of overall costs taken over, say, three years, a very different picture emerges. It is not just the saving in manpower which has to be considered, but also the faster weighing rate achieved, the large volume of data which can be collected and recorded very quickly and, perhaps most important of all, the accuracy of the information recorded on both ticket and computer.