Guard stone

A guard stone, or chasse-roue (French lit. "wheel chaser"), is a projecting metal, concrete, or stone exterior architectural element located at the corner and/or foot of gates, portes-cochères, garage entries, and walls to prevent damage from vehicle tires and wheels.

Guard stones were developed as an item of street furniture during the era of horse-drawn vehicles, but some are still in use today. They are sometimes used as traffic bollards, but are generally positioned to protect a specific object, such as a corner of a building or the side of a gate. In Paris, they are usually metal in the shape of an arc, ball or cone. There are also models in hard stone with a sloping back to guide errant wheels away from impacting a building. Guard stones made of stone were sometimes surrounded by a metal ring to reduce wear.

The wheels, including the hub, of horse-drawn vehicles protrude beyond the vehicle's body, and are thus prone to collide with and damage a corner of a building or gate. Today, early guard stones are considered cultural heritage objects and some countries, such as France and Belgium, even protect them under specific heritage regulations.

In cities the older guard stones as a concept have been replaced by objects meant for automobile traffic, such as curbs and guard rails. As a city maintenance object they slowly became obsolete and were discarded or reused for other city purposes. When they were incorporated as part of a building's structure however, they were difficult to remove and many remain as silent witnesses to early traffic on historic roads. Today such objects are treasured for historic reasons and are often protected as part of a city's cultural heritage.

Deflecting stone in Northern Ireland

Corner chasse-roue in Paris

A guard stone in Kitzingen, Germany

Passage Saint-Paul, Paris

Haussmannian guard stone

Guard-stone in Angoulême, France

Today, there are facilities with a similar purpose, but for cars. For example, these devices are installed at the entrance of a garage or car wash.

Deflecting stone in Strabane, Northern Ireland

Guard stone in a car wash station

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Wikipedia