Wish these brutes only put on 15mm thick growth.
I recon they grow around 1.0 - 1.5 mtrs a year and in that time the lateral growth is around 25/30mm thick .
Perils of having a Leylandii hedge,but as we have a Primary School playground at the back of our garden we need a screen and a sound barrier
Same here, but we live in an end house so have them all the way around the outer boundary. My gear is all petrol as I have to go around the other side and a lead would be impractical. Mine are now down to about twelve feet tall but are still about eight feet across. I use a petrol multi tool with one metre extension poles, so it can go just over three metres long, but you need arms like Popeye with all of the extensions on. I use twelve foot, wide rung steps and the petrol pole hedge trimmer attachment for the sides and most of the top but add the chainsaw attachment for the thicker bits. I use my petrol chainsaw to cut the trunk about a foot lower than the outer sides so that trimming for the next two or three years is much easier. You can't see the hollow middle from the ground, only from a bedroom window.
As amba said, the small stuff is only any good for the outer sides and nowhere near man enough for topping 35 year old Leylandii. I have to use the petrol pole cutter just to reach across the tops as they are too wide to be cut from the ground with the angled cutter and the angled trimmer won't cut through branches about ten inches thick.