Dolphin (structure)

Under a Dalbe, Dalle, or a dolphin, Dälben, or Duck, Duk - or Dückdalben, is understood to be rammed into the harbor foundation piles for attaching or reject ships or for marking the fairway.

Term origin

The origin of the name is controversial: on the one hand, it can to the Duke of Alba ( Duc d' Albe ) refer that made up such facilities in ports of the formerly Spanish Netherlands, to accommodate additional ships in a harbor. On the other hand, can also be derived from the Dutch word for pile ( Dalbe ) of the name.

Design and function

Technically, dolphins in the river bed clamped piles or pile groups under horizontal load. The river bed is generally the naturally occurring soil, while the authoritative horizontal load is usually caused by the impact of a ship.

You can dolphins for various purposes by roughly divided into two groups:

• Berthing, Führungsdalben or Abweisdalben: They serve the purpose of the application, execution and repelling of ships and the marking of the fairway. To avoid damage to vessels, these dolphins must be as elastic as possible. The occurring large collision energies are converted by the strain energy of the Dalbens and the subsoil.

• Vertäudalben: They serve the purpose of mooring and Verholens. Here rigid structures are more suitable. Even when you drop is a rigid as possible dolphins beneficial.

Dolphins were mainly made of wood until the 20th century. This building material is, however, increasingly given way to steel the material in the course of that century. Steel qualities today with very high yield strength is used to achieve the required elasticity for the Dalbenbau in many cases.

For the calculation and dimensioning of the dolphins there are different methods in structural engineering:

Dalbenramme

Below pointed Holzdalben be driven with a Dalbenramme into the ground. It is a case weight ( ram ), which pulled out on a vertical rail and fall down with gravity on the Dalbenkopf. The ram is mounted on a ship and is driven to the site.

House Duckdalben

Under the name of sailor Club Duckdalben the German Seamen's Mission in Hamburg operates a house as a focal point for all seafarers and offers them pastoral care, practical support and help in emergencies.