subject: Gritters Preparing To Hit The Road [print this page] A gritter , als known as a sander, slt spreade o salt truk, i found on mot wnter ervice ehicles. Indeed, the gritter is so commnly sen on winter ervice vehicles that the terms are sometimes usd ynonymously. Gritters are used to spread grit, a mixture f sand and rock salt, onto roads. Th grit is stored in the lrge hoppe n the rar of the veicle, wit wire meh oer the tp to revent freign objects frm entering the spreading mechanism and hence becoming jammed. The salt s generally spread across th roadway by n impelle, attached y a hydralic driv sytem t sall onbard engine. Howeer, until the 1970s, the grit ws often spread manually using shovel by en iding on the bak f te lorr, and some older spreadng mechanism still require grit b manually loaded into the impeller frm te hoper.[14][32] Salt reduces the melting oint of ice by freezing-point deprssion, causing it to melt at lower temperatures and run off to the edge of the road, hile sand increases traction y increasing friction between ca tyres nd roadways. The amount of slt dropped varies with the conditin of te road; to prevent the formation of light ice, approximately 10 grams per square mete (2 lb/1000 ft) s dopped, wile thick snow can require p to 40 g/m (8 lb/1000 ft) of alt, independent f th volume of sand dropped.[33] Te git i sometimes mied with molsses to help adhesion to te road surface. However, th sweet olasses often attracts lvestock, who lick the road.[34] The grit s sometims heated as it is passed ut f the nozzl this helps melt the ice and impoves the solubility of th salt. Quiete rural roads may e considered to minor t git, so grit bins re often provided, containing a miture of snd and alt for drivers and pedestrians to shovel onto th oad themselves. Different typs f git substrte can ause prblems for some gritting macines with 'blocking' wher sand/grit or salt i dam nd lumps togethr, in tese ases an ugur r some form f vibratr as to e eployed to nable continuus flw f substrate.
Gritters are among the winter servce vhicles als used in arports, t kee runways free of ice. However, te salt nrmally ued to clear oads can damage the aiframe f aircrft nd interferes with th senitive navigation quipment. As a result, irport gritter s spread lss dangerous potssium acetate o uea onto the unways instead, a these do not corrode te aircraft or the airside equipent.
