An access mat is a portable platform used to support equipment used in construction and other resource-based activities, including drilling rigs, camps, tanks, and helipads. It may also be used as a structural roadway to provide passage over unstable ground, pipelines and more. Depending on its application, an access mat may be called a rig mat, swamp mat, industrial mat, ground protection mat, road mat, construction mat, mud mat, mobile mat, safety mat, or portable roadway. Because there is no body governing or standardizing terminology (nor design and construction), and terminology inconsistencies are compounded by regional and industry-specific vernacular, the types described below should be considered a general guide to access matting. Types There are three general categories that describe access matting: Construction Mats Construction mats are used to provide relatively clean, smooth, all-weather working, walking and driving surfaces in industrial or commercial construction settings where access would not otherwise be guaranteed. This category of mat reduces crew downtime, increasing the likelihood of timely task completion. Construction mats have multiple applications, including: Oil and Gas sector: temporary roads, platforming on leases, pipeline terminals, and facilities Power lines: tower erection Electrical sub-stations Construction of buildings and warehouses Residential housing projects (especially where local bylaws penalize depositing mud and dirt in situations where it may wash into storm drains) A subset of construction mat, pipeline mats, may be considered construction mats, though they often begin as a different type of access mat. Pipeline mats are typically mats at the end of their productive lives, used as a rough, one-time access setting. Access Mats Access mats are a category of matting that are generally used to provide temporary roads and worksites. Access mats are often used to access work sites in remote or environmentally sensitive areas, such as bogs, wetlands or fens. For that reason, they are often referred to as swamp, bog or wetland mats. Swamp mats are based on a design developed by Joe Penland in the late 20th century and consist of three layers of 2’ x 8’ lumber laminated together with steel bolts. Most commonly, the top and bottom layer are made up of 11 pieces and the middle layer, placed cross wise, is made from 21 pieces. In the USA, the majority of swamp mats are made from mixed hardwoods, although they are often referred to as oak. It is also usual to find hardwood mats in Canada,