Jeff Probyn: The good, bad and ugly of the scrum machines

So at last we have the answer to all scrum problems – the new scrum machine being used by Bath Rugby is so advanced that it can tell its operators where all faults lie.   This new custom-made machine is so sensitive it can tell when a player is pushing at the wrong angle or in a way that would fall foul of the new engagement sequence and sounds an alarm.
Designed and built in conjunction with Rhino and an engineering company, it links a computer to what looks essentially like a usual scrum machine but with a few extra knobs and whistles.
I must admit that I am amazed at the claims that it can detect what it presumes is a wrong angle and that it can also predict all the different referee interpretations of how the new engagement sequence is to be played out and change the way a front row bind and push.
I am a bit of a sceptic when it comes to scrum machines, having used so many over the years and found that fundamentally they are good at one just thing – and that is to help timing.
Timing in a scrum is very important, simply because a team that collectively pushes at the same second will generate a far better pressure than one that is even slightly ‘off'.
The first scrum machine I used was at Bath University. It was a hydraulic machine with absolutely no sophistication. You pumped a lever until the pressure gauge labelled ‘Schools', ‘Club' and ‘International', reached the desired
pressure. The pack would then engage lock-out on a special surface to aid grip, a switch was released and wham!
The full pressure was released in an instant, making it virtually impossible to hold and very dangerous.  The first time they released the pressure I was literally pushed through the back of my boots because the pressure split the seams.
Then with England there were various Rhino machines bought along to training, all promising they would help improve our scrum (not that it needed improvement as it was regarded as one of the best in the world at that time).
These included a number of pneumatic machines capable of any number of different manoeuvres including changing angles on opposite sides of the scrum, pushing one prop up and the other down.
We even had what sounds like a prototype of the new Rhino used by Bath, a machine with a computer that could tell force of engagement and pressure exerted by each side of the scrum and the pressure passed through each of the front row.
It was supposedly so clever that it would automatically adjust to how you scrummaged against it, so if you tried to drive up, it would drive you down and if you drove down, it would drive you up in an attempt to force you into driving straight.
As a relatively small prop, one of the ways that I would combat bigger, strong players was, as pressure came on, I would drive down and once the opposition were at tipping point, drive up and straight through them.
This would relieve the pressure and enable me to lock and then drive the scrum without having to cope with the massive pressures that are generated in an international scrum. Also it took the pressure off my second row, allowing him to rest in preparation for when we needed to drive.
When put against the Rhino prototype I did the same and Phil Keith Roach who had been brought in to operate this piece of high tech equipment said: “It's no good trying that Jeff, you won't be able to get under this!”
He was wrong. I slipped under the pad and, when Wade Dooley began to drive, our side of the machine lifted and broke the computer.
There is also a dark side to scrum machines, particularly the pneumatic/ hydraulic machines that few talk about and that is the danger of injury if you get it wrong or if you have a weakness.
Back in the 1991 World Cup, England used a pneumatic/hydraulic type scrum machine as part of our training along with live scrums.
We always finished the sessions with scrum work while the backs would return to the hotel to wash their hair etc.
At the end of our final full training sessions before we faced Australia in the final, we went to the machine to do the usual 20-30 scrums just to make sure we were focused.
We started the session with Jason Leonard, Brian Moore and me as a front row with Paul Ackford, Dooley, Mick Skinner, Peter Winterbottom and Mike Teague making up the back five.
After about 20 scrums, forwards coach Roger Utley suggested a substitute for the final few scrums and Paul Rendall (the Judge) stepped in on the loose head side.
We packed down against the machine and the hydraulics were switched to slowly increase pressure which we were expected to hold.
As the pressure increased we heard a noise that sounded like a piano wire breaking, with a series of pings followed by a crack like a gun shot.
As the scrum broke up we saw the Judge hopping on one leg obviously in pain. He was rushed to hospital and diagnosed with a torn Achilles tendon, which effectively ended his playing career.
The thing is, scrum machines are unforgiving lumps of metal unlike a live scrum and are used without a thorough training regime for all who operate them.
Scrum machines, whether Rhino, Predator or any of the many other makes out there, have a place in the game and can help develop your effectiveness through cohesive timing – but they can never replicate the true pressures and angles faced in a live scrum. Nor, despite the claims made about Bath's new machine, can they read a referee's mind.