This type of security fencing is often used to protect industrial sites and other sensitive areas.   It has cast concrete posts about 7 feet high with an angled arm on the top, making the posts around 9 feet high in total.   It normally has chain link fencing about 6 feet high and three strands of barbed wire running along the angled arm.    Examples of this type of fencing date from the early 20th Century through to modern times.  

This type of miniature fencing is a real challenge to model, particularly in N gauge, but take a little care during assembly, and with this kit you can build a model fence second to none.  The kit comes with laser cut wooden posts which need to be painted to simulate concrete and 1m of grey cotton to simulate the barbed wire.   As can be seen from the cover photograph, the final effect is stunningly realistic!   A comprehensive set of pictorial assembly instructions are included.

300mm of fence.