That pylon they pulled into the centre they bulit is massive

Thank you.

It was a first for towers to be erected using a helicopter in the Uk. It was great to be a part of the project.

@@leestevenson401 I've got a question about those large lattice pylons around the UK, just something I've always noticed but never really asked anyone about. Besides me having noticed several different sized pylons (the largest size has a middle arm longer across than the top and bottom arms, where the second biggest usually has all 3 arms the same lengths across), I've also noticed 2 main types of pylons with all of the sizes, some have insulators on the end of each arm hanging straight down, where others have the insulators sticking out forwards and backwards with the wires making a downward circular loop connecting between them. What are the differences between the 2 types of pylons? Besides, I mean, that it seems that the pylons with the looped forwards backwards insulators apparently change the direction that the electrical wires are going, and the straight pointing down insulators don't. But, are there other differences between the 2 different types of pylons besides that?

@@alvexok5523 ex National Grid linesman here. So National Grid, owned and maintained the grid towers at 400,000Volts and 275,000volts and so with the higher voltages there needs to be higher clearances to ground, trees, buildings etc. So a standard height 400,000volts L6 tower is 164 feet (50m) high. These are one of the types with the longer middle arm for example. The Suspension towers are the ones with insulators that are suspended vertically and just take the weight of the conductors and are classed as D2 towers, i.e. where they are used in a straight line or up to a maximum overhead line route deviation of 2°. Any greater deviation to the overhead line route than this would require a Tension tower, which is where the insulators hang vertically and take the tension of the conductors, examples of Tension towers are a D30, D60, D90, where each number is an indication of how much line route deviates from a straight line. In other words, suspension towers for straight lines (cheapest cost from A to B is a straight line) and tension towers for turning corners. Tension towers can have very short arms on one side (circuit) and very long on the other side as in a D90 for example where the route needs to turn through a corner of between 61° and 90° (A D60 tower would be used if the angle of deviation was between 31° and 60°, a D30 tower would be used if the angle of deviation was between 3° and 29°). Sometimes a standard height tower isn’t tall enough for adequate clearance of conductors to ground, a number of 10 foot extensions are put in at the time of erection. Consequently, sometimes the standard height tower is too tall in places such as surrounding an airport and then a number of 10 feet sections of the tower are removed from the design or a special low level design of tower is used which isn’t very tall and with one long crossarm that carries both circuits conductors at the same height and the conductors are hung from twin sets of insulators strung at 45° in a “V” shape. Terminal towers are interesting in their design too, these can be found at substations and cable sealing ends (where conductors go underground) as the top cross arm is usually the longest, then the middle crossarm is second longest and finally the bottom crossarm is the shortest. L6 is one of many designs of towers, there are also L2, L3, L4, L9 to name but a few and each design are for some other purpose such as different voltages, different conductor bundles, an upgrade to a previous design etc.