Ramps and Retaining walls

On many bridges the walking surface is above ground level. In order to make bridges accessible to all users and wheeled traffic ramps are desirable. Ramps can be supplied in the same material as the bridge. This is attractive but on some occasions solid ramps are required. The most cost effective way to provide these is in compacted MoT Type 1 compacted in 300mm layers. It is best to lay this on a geo textile. When this kind of material is used retaining walls may be required to prevent the fill escaping under the bridge over time. The retaining walls can be cast at the s...
Read More

Lancashire County Council

Lancashire County Council have a long standing process for supplying attractive bridges at very cost effective rates. They have their own standard designs, buy the materials locally, construct foundations in an unorthodox but satisfactory way and erect the bridges for modest costs. They use kerb stones with great ingenuity and have developed an “entire civilisation” based on this approach. Sophisticated and complex sites have been tamed with this approach. As with any success there are critics! Disabled Activists protest that the narrow width and steps prevent a...
Read More

What is a feasibility Study?

We come into contact with people from all walks of life. Many are very successful in their field. They find themselves involved in planning, raising funds for or providing a bridge for perhaps the first (and only) time in their careers. Unsurprisingly they need information but don’t always know what information they require. They take the approach most experienced people take. They make an enquiry at number of suppliers and ask for information and prices. The suppliers ask for certain basic information and when the potential client supplies it the suppliers provide the prices and...
Read More

How long can a wooden bridge get?

Wood has been and is still used for long span bridges in Scandinavia and the US. They are often covered to provide additional weather protection to the structural timbers. In the UK we are more conservative and tend to go to steel for the load bearing elements at shorter spans. The most commonly required bridges are less than 15m for pedestrian and cyclist users. Wood is the most economical solution up to about 8m span. Once this length is exceeded the size of the sections required and their availability in timber of the quality required are deterrents. The Bridge En...
Read More

What is Ekki?

Ekki is the most popular hardwood used for making bridges. It comes from The Gabon in West Africa but is usually sourced via Holland. A Francophone nation – interesting fusion of African and French cultures! It is a Tropical Hardwood. It is however grown in accordance with the Forestry Stewardship Council processes and is FSC Certified. There are ethical issues to do with the carbon used to deliver the material to Europe. The oil used in marine transportation is the dirtiest and most polluting – used by shippers because it is cheap. It is suspected that virgin f...
Read More

Why have cranked parapets?

Why have cranked parapets? People are not the same width. Their width at ankle level is small. They get wider at Hip Height and maximum width at shoulder level  particularly if carrying a rucksack. Narrower decks have lighter loads and can have smaller beams Unfortunately the posts taper and are weakened especially the coring strength of the wood near the fixings We can offset this by using wider washers or plates.      
Read More

What are the best fixings for wooden deck boards?

What are the best fixings for wooden deck boards? When fixing Deck Boards we need to ensure they are securely fastened down and that they cannot be easily removed by vandals. However we also need to make it possible for the deck boards to be lifted (by authorized people) in order to inspect the bridge at regular intervals and if necessary to be able to repair or maintain it. Wooden deck boards are invariably fastened to timber. This will either be wooden beams or wooden Stringers fastened to the top of steel beams. It is important that these stringers are not damaged by the fixing....
Read More

Why have parapets?

Why have parapets? Parapets are provided to prevent users form falling from the bridge. If you provide them it indicates you recognise the hazard.  The question then arises if one parapet is sufficient? In some locations there would be no injury and in others the fall could be fatal The User Type is an issue. Small active children can get through or climb on a parapet leading to a possible incident. In some locations when danger is high a 100mm sphere should not pass through any opening. The parapet height is intended to prevent a person falling ov...
Read More

Kick Boards

On scaffolds, on building sites, kick boards are quite rightly mandatory. They prevent tools or materials being knocked off to fall on people working below. When bridges cross rivers this is not relevant When bridges cross other paths it is good practice but is not always observed. If the kick board is in direct contact with the deck it will trap debris. Soil will build up and plants establish. The combined effect will keep the wood permanently wet and the life of the timber will be reduced, On equestrian bridges The British Horse Society recommends high kick boards -&n...
Read More

Boardwalks are a blessing

As a measure to protect sensitive environments, prevent erosion and make it practical for members of the public to enjoy wild spaces, without feeling at risk, boardwalks are the solution. They can be used on the coast, in moorland, march, mountain or farmland. In some locations they are highly seductive and draw people away from the hubbub of life into wild and special places. They provide a proximity and intimacy with the environment without comparison. Less mobile people feel secure on them, provided they are correctly designed and are structurally sound. Small k...
Read More