It seems hard to imagine now, but there was a time when thieves weren’t very interested in stealing tractors.

There were plenty of expensive cars out there to nick, so why bother with low-value tractors?

But as car makers improved their security, in particular fitting sophisticated coded keys that were almost impossible to crack, thieves started to look for easier pickings.

They soon realised that the average tractor cost anything from £50,000 and £100,000, had less security than a wheelbarrow and was routinely left with the keys in the ignition anyway. No surprise, then, that tractor thefts started to rocket.

But technology, as ever, soon came galloping to the farmer’s aid. Not from tractor manufacturers, who reckoned that farmers would not be prepared to pay for the sort of high-tech keys used by car makers, but from GPS tracker makers.

Tracking technology dates back to the early 1990s, when a company called Tracker started using a VHF system for locating expensive cars that had been stolen. Once the owner had spotted that his gleaming Jag/BMW/Aston had gone from the drive, Tracker would switch on the vehicle’s VHF transmitter.

The signal would first be picked up by one of its network of receiver masts, giving a rough idea of where in the country it was. Then a police car fitted with a VHF receiver would be dispatched to follow the signal and, hopefully, fund it lurking in some wood.

When GPS became available in 1994, it made it simpler for manufacturers to fit an unobtrusive black box in any vehicle that would know where in the world it was and to send its location back to the owner.

GPS tracker manufacturers soon cottoned on to the relative simplicity of the technology and there are reckoned to be 150 different trackers on the UK market.

* What does a GPS tracker do?

The basic principles of GPS tracking are pretty much the same on all units. Once a machine is stolen, a tracking device about the size of a paperback hidden within it will switch on.

This could be because the owner spotted the theft and switched on the tracker remotely. Or because it has detected that it is moving.

Or, maybe because the owner has set what’s called a geofence. This is an electronic perimeter that typically would take in the nearest set of roads outside of the farm. If the tracker unit has spotted that it has physically moved outside that area it will wake up and start transmitting its position.

To do that, it has a SIM card so it is able to communicate with you over the mobile phone network.

* Does accuracy vary from unit to unit?

Standard GPS accuracy, whether it’s on a car satnav or on a smartphone, is about 30m. Stolen tractors and 4x4s are often taken by the thieves to a local wood for a couple of days to see whether the owner has fitted a tracker and will come and find them.

If they don’t, then the thieves know that they can start to move the vehicles to a port or other destination.

* Won’t the thief try to locate the tracker and remove it?

Some thieves will try to find the tracking unit and the skilled ones may be successful. However the firms that fit these devices have become pretty adept at burying them in places that are hard to get to. The units are becoming physically smaller, too, which helps.

* What if the vehicle is hidden in a shipping container?

Full-size tractors are too tall to be hidden in a container, however pick-ups and 4x4s go in neatly. The GPS signals from your tracker can’t penetrate steel, so if the thief has done that, you’re a bit snookered.

However some tracker firms bring other technologies to bear on the problem. Even if the GPS signals aren’t getting through, most systems are able to use GPRS (mobile phone voice) or, better still, SMS (mobile phone data) signals passing to and from between mobile phone masts to triangulate in on your stolen vehicle.

And one or two firms have UHF or VHF systems to allow them to pick up the faint signals that leak out through vent holes and gaps around doors in shipping containers.

* How easy are they to fit?

Some units can be fitted by the farmer, others have to be fitted by the firm you’ve bought from. Self-fit is cheaper, but the job must be done properly if the tracker is not to suffer from moisture, vibration or dust.

Professional fitment is more expensive, but the firms involved point out that their experience with fitting units on a wide range of vehicles means they can hide the units better and ensure that they are kept dust and moisture free.

* Engine-powered or battery powered?

Battery-powered units are designed to be concealed on machines that haven’t got a power source, eg a stock trailer. They only wake up when the machine is moved or goes outside the geofence but the bigger battery means they are physically more bulky.

Units that take power from the vehicle’s electrical system are able to be somewhat smaller.

* Do I deal with the whole thing myself or should I use a firm that does it all for you?

It depends how hands-on you want to be. Cheaper units leave it to the farmer to receive the stolen vehicle alert and deal with it himself. More expensive ones tend to route the alert to a call centre who will deal with it (though you’re kept informed).

* How will I know if the vehicle has been stolen?

The first thing you’ll get is a text and/or email telling you that the vehicle has moved. If that’s Bert heading off to finish off the ploughing in Long Field, you need do nothing more than text back or ignore the alert to avoid getting more texts to tell you Bert’s every subsequent movement.

However if it looks like your tractor or 4×4 has been stolen, you now have the means to see where it is heading. Head for the computer in the farm office (or, better still, whip out your smartphone) and you’ll be able to see where your vehicle is to 30m satnav-style accuracy.

You can’t actually see it moving on the screen but each time you refresh the screen (ie every 10 seconds) you will see where it has got to.

At this stage you can choose to chase after it (carefully adhering to all road traffic regulations, of course…) or you can ring up your local police station.

According to the GPS tracker companies, the police are generally fairly enthusiastic about following up a ‘live’ crime, as the chances of making an arrest are rather higher than if they were following up a crime that happened hours or days before.

* What else can they do?

Many of the systems include a ‘history’ function that show where the vehicle has travelled in the last 24 hours. That means you can look on your computer or smartphone screen and see exactly how much of Long Field Bert has ploughed.

You can also keep an eye on the whereabouts of younger (or older) family members who may be otherwise hard to pin down…

Some systems can be set to automatically send you a text if the vehicle goes above a certain speed or stops for more than a set amount of time.

We fitted seven different GPS tracker systems on a Deutz-Fahr Agrofarm 100 tractor on a farm in Warwickshire. Most were either fitted by the company’s own fitters, but FW staff put on a couple of the self-fit models.

We hid what must be Britain’s most-monitored tractor in a barn at the other end of the farm. Access is solely via fields and muddy farm tracks, so it seemed like a pretty good approximation of where a thief might hide a tractor or 4×4.

We tried each of the tracking systems in turn, first by using each key feature one-by-one, such as setting the geofence, the time parameters, and the various methods of establishing contact, via email or via text message.

For the call-centre derived models, like the Tracker and the M-Track, this meant triggering the ‘stolen’ feature to monitor how this would work in practice.

For the Kramp FarmAlert, the Agritrack, the Visionaire and the Tractor Guard, this was a office-based exercise, using either the link that came through via email or text to determine the position either using the tracker’s online mapping or typing the coordinates into Google or your search engine to pinpoint the position of the vehicle.

Tracker VHF system

We were also curious as to how Tracker’s VHF system worked in practice. Tracker is not the only company to have a VHF system, but it is the only one that involves equipment fitted into police cars.

PC Pete Hayes from Greys Mallory Traffic Base at nearby Warwick was happy to take up our challenge to find the Deutz-Fahr tractor that we had hidden in a barn at the other side of the farm.

Under normal circumstances, the tip-off that a Tracker-equipped car had been stolen would have come first from the network of aerials on TV masts.

Getting triangulation of two or three of these can get the local police force to within 3-7 miles of the vehicle, however we were able to skip that bit by getting PC Hayes near (but not that near) to it.

“We have four aerials on the roof of the car,” he says. “Plus a compass and signal strength bar on a display in the police car. You basically circle around where you think the vehicle is until you’re sure.”

Having to find a tractor that was hidden in the middle of farmland sounded like it would be a relatively tough task for a 2wd car driven by someone who didn’t know the area in that much detail.

To start with, we had one or two fruitless trips down farm tracks but had to turn back because the car could go no further.

But by the time PS Hayes had done his full circle, he had a pretty good idea of where the tractor was and was able to head down a track and find it lurking in an old brick barn. Total time taken was about 30 minutes and probably would have been less had the locality had been known.

M-Track

Power source: Battery (life: 5 years – when set to wake-up every 12 hours)

Notification: Call centre 24/7 monitoring + alerts up to four phone numbers. The company says it aims to get one of its agents to you within two hours to recover the vehicle.

Fitting: Self-fit

Geofence? Yes

Telematics? Yes

Insurance discount: The MTrack is the only battery-powered unit to be Thatcham approved, and gets a 12.5% discount from the NFU Mutual

Cost: £285 for the wireless version, £325 for the wired one. Annual subscription £108.

Contact: 01329 663812 www.mtrackonline.co.uk

Features: The MTrack is an ‘off-the-shelf’ product designed to be interchangeable between vehicles or machines. It combines the simplicity of a self-fit device with the back-up of an established call-centre used to dealing with recovering stolen vehicles.

The unit can be armed in various ways, but the simplest is to use the straightforward key fob. The unit also ‘checks-in’ every 12 hours (this can be altered) to make sure it hasn’t been moved.

Up to four contacts can be listed and each is subsequently phoned or texted should the alarm be triggered. The unit continues to track until it has been recovered and, should the vehicle be loaded into something like a container, that’s when the UHF tracking facility comes into it’s own.

Verdict: Straightforward and easy to use, the MTrack is designed for those who want call centre back-up alongside something they can use on multiple machines without the hassle of re-wiring.

Tracker Plant

Power: Hard-wired into tractor

Fitting: Installed by Tracker-approved specialists

Notification: Call centre and Tracker will contact you to alert you of the theft

Geofence? Yes

Telematics? Yes

Insurance discount? Thatcham-approved, and attracts a 12.5% discount from the NFU Mutual

Cost: Installation £385 + sub of £160.85

Contact: 0845 602 2356 www.tracker.co.uk

Features: Tracker Plant is the top-of the-range offering from Tracker and uses GPS as well VHF to locate stolen equipment, a little like the Mtrack model.

However, Tracker is the only manufacturer to have receivers in police cars (as mentioned earlier) and the Plant model is also able to provide a whole list of fleet management options, as well as geofence and time parameters. It’s also fitted with a signal-jamming detector to alert of the last known location.

Verdict: Perhaps the best-known name in tracking, Tracker has branched out to offer a sophisticated fleet management tool as well as a police-supported network to track down stolen machinery. But if it’s purely security you’re after – go for the cheaper Tracker Retrieve option.

Carrotech Visionaire

Power: Hard-wired into tractor

Fitting: Install it yourself, comes with wiring diagram. Or use a registered fitter.

Notification: Self-managed from the farm

Geofence? Yes

Telematics? Yes

Insurance: Contact your insurance advisor

Cost: £250 one-off fee; £66/year for data Sim card, which includes 5mb data/month and 10 texts. After the 10 texts, cost is 8p/text. Customers can use own Sim card if they wish.

Contact: 0845 557 5594 www.visionairegps.co.uk

Features: The Visionaire tracker unit wakes up when the ignition is turned on and equally if the vehicle is towed away. The system can be armed using several different methods, including a rocker switch fitted to the tractor, a key fob or using time and location settings.

It also offers a telematics service, which enables owners to monitor things like engine hours, ignition on and off times, speed and real-time position status.

It’s also possible to set remote immobilisation on certain vehicles, if the unit has been hard-wired into the ignition system.

Verdict: This is a great all-round device that allows you to keep an eye on where your machine is and how it’s being used. The security settings are thorough and the interface is easy to use.

Kramp Farm Alert and Farm Alert Standalone

Power source: Farm Alert is hard-wired and Standalone is battery powered (5 years in standby mode)

Fitting: Self-fit or local dealer

Notification: Self-managed from the farm

Geofence? Yes, set using boxes drawn on the website

Telematics? Yes, on Farmfleet

Insurance discount? Depends on your local insurance broker.

Cost: £395 for Standalone, Farm Alert and Farm Fleet. The Farm Fleet offers telematics-type options and costs up to £1 week to use. No sub for Standalone and Farm Alert.

Contact: 01767 602602 www.kramp.com

Features:

The Farm Alert tracker starts tracking automatically if the vehicle moves out of the timed periods and if it moves outside the geofence. Once it’s tracking – it’s possible to interact by text from your mobile. It’s also possible to have an immobiliser fitted to the device that can be hard-wired into the fuel valve or forward reverse shuttle.

You can even arm the proximity fence from the pub by texting ‘fe’ to the number of the sim card. The Farm Alert also features a list of telematics options like engine hours, speed, position and ground work data.

The Standalone unit is completely transferable between vehicles, and for the purpose of the test we fitted it to an Ifor Williams stock trailer. It comes with a key fob that can be activated or alternatively the unit can be set to automatically trigger should it leave and area or move outside a certain time.

Verdict: Having tested both the hard-wired and battery powered versions of the Farm Alert, we were impressed by the level of detail available for fleet management. We also liked the accuracy of the Standalone unit and the fact that it’s so easy to fit to easily stolen items like trailers.

Tractor Guard Tracker

Power source: Hard-wired

Fitting: Self-fit or local dealer

Notification: Only by text

Geofence? No

Telematics? No

Insurance discount? Depends on your local insurance advisor.

Cost: Full kit, including pay-as-you-go sim card costs £299 + VAT. No sub.

Contact: 07815 796643 www.tractorguard.co.uk

Features: To locate your machine, simply text it with a command and it will send a return text with longitude and latitude that you can either look up on an OS map or online using any search engine.

It’s also possible to immobilise the vehicle, be it quad or tractor, as long as the tracker has been wired to include the ignition.

By texting ‘stop’ the vehicle is immobilised and by texting ‘start’ it’s in work mode once again. A movement sensor within the tracker box alerts the owner should the machine be moved without the ignition on (for example a quad that’s being put on a trailer).

And, should the quad or tractor turn over, a tilt sensor texts both the owner and another contact (since the owner is probably the driver) when and where the accident has happened.

Verdict: We found the Tractor Guard unit very simple to use and brilliant for quad and utility vehicles. A great feature is being able to remotely immobilise vehicles should you want to without having to log on to a computer. It’s also very good value.

All of the tracker units did what they promised to, sending texts or emails to the owner when a tractor or 4×4 has been illicitly or illegally moved. Of course, if you keep the system switched on, you’ll get an alert every time the tractor is moved, which can get a bit tedious, and uses a lot of your credit if you’re on a pay-as-you-go system.

The main differences between the units are in sophistication and cost. Broadly, there are two types tested. Two units, the Tracker and the Mtrack, are aimed primariliy at stolen vehicle recovery, i.e. details are sent to a call centre which then notifies the police and the owner after establishing whether the vehicle or implement has been stolen.

Both still have the scope to provide some fleet management capabilities. The remainder of the units tested use fleet management tools to alert the owner if a machine moves out of its allotted time or area, or if it’s put on a low-loader and towed away.

To this end, we received contact from both Tracker and Mtrack after the vehicle was ‘stolen’ and were also contacted by each of the other devices.