Tag:tower:type=bridge

 Bridge tower was a type of fortified tower built on a bridge. They were typically built in the period up to early modern times as part of a city or town wall or castle. There is usually a tower at both ends of the bridge.

Function

These towers were built in pre-medieval and medieval times to guard access to the bridge and to enable the charging of tolls on important roads crossing rivers, usually near towns and cities. The rivers were often part of the defences of these settlements. As a result, it was important from a defensive perspective that the bridges did not allow attacking enemies to break in. The bridges acted as a bulwark and often had a small drawbridge. In addition to their genuine protective and defensive functions they also played a symbolic and architectural role. Often these towers were the first public buildings that the travellers saw when approaching the city.

The high cost of such towers was usually paid for by charging tolls. The gates of bridge towers were closed at night, so that no-one could cross the bridge during silent hours.

Neo-Romanesque bridge towers were built in the 19th century. The purpose of those towers was above all architectural decoration but also defensive. After the bridge tolls have finally been abolished in the beginning of the 20th century, the towers lost their function and were often dismantled. Today, the few surviving bridge bridges serve as the landmark of the city and are an attraction for tourists.

How to map

Place a node or draw an area of the tower's outline. Tag it man_made=tower and tower:type=bridge (mandatory).

• building=yes - bridge tower is a building.
• building:part=yes - when 3D mapping it is necessary to tag the part of the way under the tower with min_height=* + layer=1.
• historic=yes - bridge tower has a historic value.
• heritage=yes - it is protected by some heritage organization.
• height=15 - the tower is 15 m high - an estimate will do.
• name=* - name of the tower, also alt_name=*, loc_name=* or old_name=*

Ways and layers under tower bridges

If the bridge tower is standing on the bridge there is usually one more more ways (highway=* or railway=*) going through it.
Consider to add the tag barrier=sally_port here.
Tag the bridge tower with the same layer=* as it is on the way going through the tower.
Try to determine the height of the passage (maxheight=*) and tag it on the appropriate way segment.
This way segment can be tagged as tunnel=building_passage or for very short way segments covered=yes.

Examples

• 

  Prague - Charles Bridge - Old Town bridge tower

• 

  Worms Nibelungenbrücke

• 

  Berlin, Spree, "Insel der Jugend" - bridge tower

• 

  Bridge tower Regensburg, Germany

• 

  Limburg - Old Lahn bridge

• 

  Traben-Trarbach, late Neo-Gothic tower bridge over Moselle