Tapio 600: Simon Bowes provides an update on harvester head restoration project

IT’S a good question. What has happened to the Tapio head I was rebuilding? Well, quite simply, it’s still sitting in the corner of my yard, because there’s only room for one head on a harvester and the machine I was going to mount it on has only just become available.

I shall explain why the capricious world of timber harvesting has made me change my plans. I may be someone you think has a handle on everything and doesn’t often make huge cock-ups. I can tell you nothing could be further from the truth. I’ve made more than my fair share of bad decisions, but this time it was unforeseen circumstances that I blame for this particular faux pas. It’s a tale of a broken casting, missing parts, dubious windscreens and a whole host of secondary issues caused by a virus – and it all started with a barely audible click that stopped a harvester crane slewing and ended with a brand-new windscreen that I couldn’t see through.

READ PART I: Forester Simon Bowes considers repairing an old Tapio harvesting head

I was back at work after another of the lockdowns, forwarding on the ash clearfell we had just started, when I had a call from the harvester driver to say he’d lost slewing on the crane. He’d just moved some brash off the track in front of the machine and the crane wouldn’t come back to the centre. I think I’d hauled about 20 tonnes of the 200 or so laid on the forest floor. I remember thinking: “Welcome back friend, forestry’s got a surprise for you.” This is one of those moments when the eventual outcome is inevitable, but you just hope that, somehow, that gnawing fear you have is unfounded. If a crane won’t slew it can be an electrical fault that needs a poor connection repaired, which only takes 10 minutes and costs nothing. Or it can be a broken slew pinion which takes many months and several thousands of pounds to put right. Guess which one I was looking at.

With the harvester on the road we opened the cover on the valve block and, with the engine on tickover, I operated the slew valves manually. It slewed one way perfectly, but it wouldn’t move back the other way. I asked Richard to put the working revs on and tried the slew solenoid again. This time there was a noticeable click and, watching the crane base bushing, I could see the king post trying to climb out of the base.

FJ (Image: FJ)

The damage was confirmed when we took the slew cylinders off and watched as I pulled the crane round with the forwarder. The crane moved, but the slew racks didn’t. The pinion gear on the bottom of the king post was sheared off, which meant removing the crane and replacing the king post and possibly both slew racks. It had been three years ago that one of my older 1270s had broken two gear teeth off a slew rack and replacing the crane base had been the only option. It wasn’t something I was looking forward to doing again.

This 1270 with the newly broken crane was fitted with a 630 Viking head that had been refurbished around 12 months before, when I’d bought the machine, but I had already decided I wanted to change it. I’ve used Viking heads for years, but there are too many uncertainties about the future supply of parts for the type, so I’d done a deal to trade mine for a nearly new Logmax 5000, which was sitting on a pallet waiting to have a light refresh before being fitted.

The question now was how to keep the timber moving on the ash clearfell, as this is always a time-sensitive operation. Harvesting on that ground is very weather dependent, and firewood needs time to dry before it can be sold on to the local firewood clients, especially now there’s that 20-per-cent moisture rule. The Tapio project would have to be put on hold and the 625 Viking I’d traded in with my other, older 1270 was secured in a deal so we could refit it and keep on working. 

To clear a couple of points up that might cause some confusion... I was previously running two 1270 Timberjacks fitted with Viking heads. One had a 625 fitted, the other an older 520. I sold the 520, leaving one machine without a head, and then the other 1270 fitted with the newer 625 was traded against the newer 1270, which now had the broken king post. That 625 was sitting waiting to be refurbished and sold, or broken for spares and so was available.

We spent a couple of days fitting the head and getting the Dasa computer rewired after all the wiring had been swapped around. While we were doing it, we replaced  a load of pipes, fitted a couple of new sensors and did a bit of welding. The old 1270 got a filter and oil change, a few new pipes, grease points and a good clean before being thrown back into work. It’s a pretty basic machine, the 1270A, but looking back on several months of tough hardwood work I can say – without fear of contradiction – it’s proved itself a dependable workhorse. I can say the same about the Viking head. I originally bought that combination almost seven years ago and it’s a testament to how well these things were built that it’s back working full shifts again.

I think this is called a terminal failure. (Image: FJ)

The backwards step wasn’t well received by the driver, but as we were hand felling most of the ash and the only other option was to hand process it too, the chance of a seat to sit in swung the deal. The phrase ‘any port in a storm’ springs to mind.

Some parts are still available for older Timberjack machines. In fact, it’s remarkable how many small parts can still be sourced. Whether you can afford them or not is another matter. Going back to the current issue that needed sorting, I tried all the usual suspects for a king post but they are a rare commodity. John Deere could source one, but at £8,900 plus VAT it was very definitely a last resort. It was Iain Wilson who finally came up with a solution. He had one that needed the main pin eyes remanufacturing and it had a couple of pinion teeth that had been caught with the cutting torch when it had been stripped down. This king post was destined to go back home as a core to have a factory re-man, so to help me out Iain agreed to sell it to me for the same price as he could get for it as a core. It was going to cost quite a bit to have the pin eyes welded and line bored and the gear pinion teeth tidied up, but the damage there was incidental and it wasn’t where the pinion would mesh with the slew rack gears. It was an added bonus that the post was from a later model 1270 that had a much bigger pinion gear stub without the stress-focusing taper that often leads to the posts breaking, particularly on machines originally fitted with the brutal 762 head.

We were now in July 2021, so time had moved on to the point where we were rapidly getting to the end of the ash clearfell, but the old 1270 was still working away without fuss or drama. The newly refurbished king post was collected from Premier Engineering in Scarborough and the bill for £1,200, added to the price of the bare post, bushes, longer pins to suit the post’s broader shoulders and the costs of transport, brought the ready-to-fit unit in at just less than a quarter of the price of a factory replacement. It had taken three months to source the post and get all the work done, though. I could have had a new one within a week if I’d wanted to stump up the cash or had needed to have the machine back in service in as short a time as possible. I guess you have to make decisions with a view to what your particular situation is at the time.

With the crane refitted with new slew seals and oil it was back to working as it had before with a new confidence that it should last as long as I keep the machine. I did have the engineering company crack test the gear before they started work on the major refurbishment, so all that was required now was the Logmax head hanging on and a few minor jobs and we should have been good to go. Unfortunately, one of those jobs was resealing the windscreen. The old 1270A Timberjack harvester has a flat windscreen, but from the 1270B onwards they have a curved screen which doesn’t seem particularly significant until you discover that £1,500 for a new one buys you something that looks remarkably like a flat screen for a 1270A. In order to fit it you have to bend it and glue it in.

Unfortunately, from the second you remove the clamps that have to be used to hold it in place until the glue dries, it’s trying to return to its flat shape. It’s a common fault for these screens to leak and the only permanent solution is to remove them and reseal them. Unfortunately, once you allow them to go back flat and then try to re-bend them, they will develop millions of tiny cracks and become opaque or at least impossible to see through in strong sunlight. Don’t ask me how I know this – I just do.

The HarveMeter 2000 computer. (Image: FJ)

So with the original windscreen removed and replaced and one replacement removed and discarded, it was time to have a professional cab glazing company have a go. The new screen they fitted went in without fuss. They guaranteed the screen wouldn’t leak, the glue they used was impossible to dislodge once it was allowed to cure. And so, after 24 hours, all the protective coloured film fitted to protect the screen’s hard coating was removed and I experienced one of those WTF moments we are all too familiar with. One half of the screen was perfect, the other half looked as if it was smoked. The armoured polycarbonate sheet had a manufacturing fault and, given it had taken several weeks to get it, I was now looking at another long delay.

In the meantime, the head had been totally refurbished with all-new seals, new pins, new bushes, a full electrical service and new paint. I had considered changing the feed wheels for Moipu ones, but they were in such good condition it seemed an unnecessary expense to add to an ever-increasing bill.

The day finally came when the old 1270 was sent off on the wagon that would return with its replacement, complete with new windscreen, uprated crane and newly refreshed head and the idea that maybe I should turn my attention back to the Tapio resurfaced, but time soon moved on and it was May 2022 before it finally saw a spanner again.

So here are we now, at the back of summer, and the Tapio is all put back together. It’s been quite refreshing to work on something relatively comprehensible, although piping the knives up was a challenge as the hoses, which were all marked with coloured cable ties, were replaced with new ones at some time in the intervening months, but the cable ties were not.

It’s been something of a challenge which has nagged away at me for many years. I had a really good 600 Tapio sold to me by Tim Cronin more than 20 years ago. I never appreciated how good that head was until I bought a 400 which was perhaps more typical of an old piece of kit which had been worked hard and maintained lightly. I never really got that head to work properly and I always wanted to have another crack at running a Tapio head which was in good condition, so I’ve spent a lot of time but not really that much money on bringing the 600 Tapio out in my yard up to decent standard.

I certainly know much more about how to maintain and operate harvesting heads than I did back around the turn of the century so, as of today (although that might change) I’m on course to fit that head onto a base and put it back to work.