Delta mast

Basic shape of the delta mast

In the event of a lateral load (e.g. from wind), a delta truss can give way elastically without losing strength, and is therefore very stable.

Delta mast is a design of overhead line masts in which the traverse is carried by a V-shaped fork, with at least one conductor cable laid within the fork.

The name comes from the fact that the fork with a traverse is reminiscent of a large upside-down " Delta ".

Structure and distribution

Large delta masts are usually built from steel framework, smaller ones from simple steel profiles, but also from solid materials such as wood. The ends of the fork are often extended beyond the traverse to carry earth ropes there.

The construction with a "waist" below the crotch enables the construction to give elasticity to lateral loads, which gives it a high level of stability.

Delta masts are mostly used for a single circuit , sometimes also for two circuits up to 765 kV. This design is widespread in the USA , Canada , France , Spain , Italy and the countries of the former Eastern Bloc . Because of their high stability, they are also used sporadically in Austria and Switzerland .

In Germany , high-voltage lines laid on delta masts are rare. In the 1930s, single-circuit lines were mostly laid on delta masts in Mecklenburg and Pomerania. Some of them are still preserved, such as a 110 kV line between Schwerin and Güstrow. Identical types with this line still exist between Białogard and Gościno , south of Stargard and near Golczewo in present-day Poland.

Special shape cat fattening

If the delta not only has an overhead crossbeam, but also external (half) crossbeams on the side, one speaks in French of a pylône chat ("cat mast"), as the image of the face of a cat with protruding whiskers and two ears remind.

Examples

Germany

20 kV lines Bad Neustadt - Mellrichstadt , Hildburghausen - Schleusingen (only guy poles )

20 kV Danube crossing at Winzer

20 kV Danube crossing near Gelbersdorf

20 kV line Rudolstadt - Schwarza - Unterschöbling

50 kV line Obergräfenhain - Oberelsdorf , today operated with 20 kV. The fork is brought together again over the cross member, so that only one earth wire tip remains

110 kV line Meitingen – Memmingen

110 kV line Gröditz - Niederwartha