Ash Gate Hurdles, How to: Part 2

In this post I shall continue on from my last post, where I began to outline one method used to make ash gate hurdles. I've included quite a few photos in this post so I'll let them do most of the talking. 

Tenons are cut to size using an axe and a drawknife

I usually cut my tenons to about 5cm x 2cm though the size of your tenons will depend upon the size of your auger bit that you will be using to create the mortise joints in the uprights. 

Before boring out the mortise joints draw around the tenons onto the uprights so that you can ensure that the mortise matches the tenon. Mike Abbot suggests placing the rails 8" apart from centre to centre, this gap should be slightly less at the bottom to prevent lambs from escaping! 

Stop boring through the upright once the tip of the auger thread breaks through the other side. Then turn the piece of wood over and drill back through using this small hole as a guide. This will prevent the wood from tearing out as the auger bit exits the hole. 

I use chisels to clean up the mortise, though a twybil can be used. 

Offer up tenons to check the fit. You can always shave off more material for the tenons if the fit is a bit tight. 

Drive the rails into the uprights one side at a time.

I tend to assemble one side of the hurdle before tracing around the tenons on the other upright. I find that this helps to ensure that the gate hurdle is as straight as possible once it has been assembled. It doesn't really seem to matter if the mortise joints on the second upright are slightly off of vertical if the rail has a slight twist along its length. 

Tenons driven into both uprights

All that's left to do now is to prepare the central upright and the two supporting diagonals. These are made in much the same way as the previous pieces, they are split and peeled. Once these components have been prepared they are nailed onto the rails. Nails should also be driven through the uprights and into the tenon joints as this will help to ensure a tight fit. 

The nails should be 'clenched' as illustrated in the image below, this reduces the risk of the components being pulled apart.   

Ash Gate Hurdles, How to: Part 1

Over the last few months I've been doing a lot of coppicing and thinning of the woodland at Gressenhall museum where I work, mainly for the benefit of wildlife. In the process we've been able to collect some straight grained lengths of ash, which are just what we need to construct a few ash gate hurdles! Those of you who have read the Mike Abbot's green woodworking book will recognise this method.

Lengths of straight ash of varying diameters perfect for hurdle making. There's also some oak and hazel mixed in with this pile.

We began by splitting the rails or cross-bars of the hurdle; these should be about 5-8 cm in diameter and would traditionally of been 8 foot (2.4 m) long, though ours are about 6 foot (1.83 m) long. To split the rails I used a tool called a froe and a cleaving brake. The cleaving brake is effectively a frame that allows tension and compression to be put on either side of a length of wood, it is essential that you can control these factors if the split is to run straight through the middle of the rail.

A traditional cleaving brake made from some old fence posts, giving these posts a new lease of life! 

To use this set up the froe has to be bashed into one end of the rail with a mallet, it is important to ensure that the whole width of the froes blade is inserted into the rail before any pressure is put onto the froe handle. This will prevent it from jumping out of the split. Once the froe has been bashed into the rail you can rest the rail in between each cross beam of the cleaving brake. Then use the cleaving brake to hold the rail in place whilst pressure is put onto the froe handle to encourage the split along the rail. 

It's important to make sure that the whole width of the froe is inserted into the split, otherwise it could easily jump out of the split and cause an injury once pressure is applied onto the handle. 

Using the froe and cleaving brake to split an ash pole.

The real skill comes in keeping the split running straight along the grain. To do this keep an eye on where the split is going, if the split begins to run out so that one half is bigger than the other then flip the rail over so that the larger half of the rail is on the bottom. Then push downwards on the rail whilst also pushing downwards with froe. This will encourage the split to run straight. 

Note how the split almost zig-zags its way along the length; this is partially because of the knots but also because I am continually flipping the rail over to keep the split running straight.

We needed 5 rails in total, so split 3 lengths of ash. once these were split we used the same process to split the uprights, these should be 1.2m (4') long and about 8 - 10 cm (3-4") in diameter.

Split rails waiting to be peeled. 

Once all of these components had been split the bark was peeled off of each length with a draw knife. Though I used a shave horse to hold the piece of wood whilst I peeled the bark, there are many other methods that you could use. 

Peeling with a draw knife and shave horse. 

Another really simple but effective way of holding the rail or upright for peeling is to drive a stake into the ground next to the cleaving brake that is roughly the same height as the lower rail. A double ended nail can then be driven into the top of the stake. Place the length of wood through the cleaving brake and then onto this nail, the pressure from the two rails will hold the length of wood on the nail and prevent it from slipping whilst it's peeled (see pics below). 

Note the stake with nail on top to the left of the cleaving brake.

The pressure from the two cross beams of the cleaving brake will hold this rail onto the nail. 

Once the rails and uprights were completed they were placed onto the ground so that the mortise joints to be drilled into the uprights could be marked out. 

Over the next couple of days I'll be shaving down the tenons on each of the rails, cutting out the mortise joints in the uprights and cleaving a central upright and the two diagonal supports.

Once the gate hurdles are complete they'll be used on and around the farm. One of my colleagues at work is hoping to use them during event days to screen off an area where he uses an old Lister engine to power old fashioned farm machinery such as a beet slicer and an oat roller.