Technical glossary

Tactics, Fire Suppression – Determining exactly where to establish control lines, what to do along these lines, and how best to utilize each fire fighting resource group to cope with site-specific conditions and fire behaviour at the moment. This is a line function. Note Strategy, Fire Suppression.

Thermal Imagery – The display or printout from an infrared scanner.

Thermograph – A self-recording thermometer or an instrument that records automatically and continuously air temperature on a chart.

Thunderstorm – A localized storm, invariably produced by a cumulonimbus cloud (CB), accompanied by lightning and thunder. Synonym - Electrical Storm.

Timelag (TL) – the drying time, under stated conditions of dry-bulb temperature, relative humidity, wind speed, and time of the year, required for dead fuels to lose about two-thirds (2/3) of the difference between their initial moisture content and their equilibrium moisture content. The TL therefore represents the rate of moisture change in a fuel. Dead forest fuels can have TL values from minutes to months. The fuels represented by the Fine Fuel Moisture Code, Duff Moisture Code, and Drought Code in the Canadian Forest Fire Weather Index System have TL values of 2/3 (or 16 hours), 12, and 52 days in average weather, respectively.

Tools, Hand, Fire – The principal hand tools used in fire suppression are:

• Pulaski – A combination chopping and trenching tool, which combines a single-bitted axe-blade with a narrow adze-like trenching blade fitted to a straight handle. Useful for grubbing or trenching in duff and matted roots. Well balanced for chopping.
• Rake, Fire (Rich Type) – A long-handled combination rake and cutting tool, the blade of which is made up of a single row of mowing-machine cutter teeth. Useful for trenching, scraping, and cutting, particularly in leaves, pine needles, and light duff. Also known as a Rich Tool.
• Shovel, Fire – A type of shovel specifically designed for use in constructing a fire line, having a tapered blade with both edges sharpened. Used for scraping, digging, grubbing, throwing and cutting.

Type of Fire – Note Forest Fire (1).