Winter Conveyor Checklist

Home
Blogs
Winter Conveyor Checklist

Winter Conveyor Checklist

Field guide · Outdoor bulk conveyors

Winter finds the weak spot overnight.

A running belt stays warm. A stopped one doesn't. Here is what freezes first, and a walk-down for your site.

Most cold-weather conveyor failures start during a shutdown. Moisture freezes on the drive pulley, carryback locks onto the return idlers, grease stiffens in the bearings, and the first start of the morning finds every weak point at once.

Drive pulley

A tight belt can still slip.

Ice between belt and drive pulley takes away the friction the drive depends on. Uneven ice across the face sends the belt off track.

Deice drive pulleys before any long shutdown, and do lagging repairs while it is still above 41 F.

Crowned pulleys Flat pulleys Take-up units

Idlers

A seized idler doesn't squeal. It wears flat.

A few millimetres of ice is enough to push the belt off centre, and a belt dragging over a seized roller can overheat.

Walk the running belt now and replace any roller that growls or won't turn.

Wing pulleys Winged pulley guide

Screw conveyors

A frozen screw needs heat, not another start.

Material freezes to the trough and flights overnight. Hitting start again strains the motor and gearbox, and a screw that breaks free can lurch.

Empty screws that will sit in the cold, or heat-trace and insulate the trough.

Screw conveyors Screw conveyor parts Hanger bearings

-20 FWhere standard urethane cleaner blades stop being ratedMartin Engineering

41 FMinimum for cold-bond lagging repairsFlexco

-10 FBelow this, Dodge TIGEAR-2 reducers need low-temperature oilDodge

5,000 cStISO VG 220 gear oil at 32 F, before it has to start a gearboxMachinery Lubrication

Your winter walk-down

Pick the coldest night your site sees. Items that change at that temperature are flagged. Tick each one off as your crew works through it.

Coldest night at your site

Drive pulleys and laggingCheck thisBefore the freeze

Check: Lagging wear and delamination, and any pulley that slipped last winter.

Fix: Repair lagging now: cold-bond needs 41 to 113 F and humidity under 80%. Stock deicer and pre-treat slip-prone pulleys before shutdowns. Where wet slip is chronic, ceramic lagging grips far better than plain rubber.

Crowned pulleys Flat pulleys

Take-upsCheck thisBefore the freeze

Check: Gravity carriages travel freely with guides clear of ice. Screw take-ups have adjustment left.

Fix: Don't cure slip with tension: over-tensioning brings mistracking, bearing damage and splice damage.

Take-up bearing units

Belt cleaner bladesCheck thisBefore the freeze

Check: Each blade's rated low temperature against your coldest night. Re-tension every cleaner.

Colder than -20 F: standard, low-rigidity and low-adhesion urethane blades are out of their rating (Martin Engineering). Fit a grade rated to -40 F, or carbide.

Standard urethane blades are rated to -20 F, so you are inside their range.

Fix: Carbide suits fine, wet or sticky material, but Martin advises against it on belts with several mechanical splices.

Conveyor parts

Idlers and rollersCheck thisNow, belt running

Check: Walk the running belt and listen. Look for ice rings and flat spots on return rollers.

Fix: Replace any roller that squeals, growls or won't turn. On belts that ice up every year, consider plastic shell or disc return rollers.

Wing pulleys

Bearing greaseCheck thisBefore the freeze

Check: Regreasable pulley, take-up and hanger bearings.

Fix: Switch to a cold-weather grease before the first freeze. For very low continuous temperatures, NLGI suggests a synthetic base oil in a softer NLGI 1 grade.

Take-up units Hanger bearings

Belt covers and splicesCheck thisBefore the freeze

Check: Cover compound rating and splice condition on every belt that runs outdoors.

Colder than -22 F: Semperit says standard belt construction turns brittle and prone to cracking. Plan replacements in a cold-rated cover.

Standard belt construction is fine at this temperature. Check the splices anyway.

Fix: Keep a mechanical fastener kit for each belt on site: a fastener splice takes under an hour, a vulcanised splice four to six.

Get a belt quote Belt fasteners and accessories

Screw conveyorsCheck thisBefore the freeze

Check: Hanger bearings, coupling shafts and trough covers. Which screws will sit idle in the cold?

Nights at 20 F or colder: empty any screw that will sit, or heat-trace and insulate the trough.

Above 20 F, keeping screws turning overnight usually stops them freezing in.

Fix: Never keep hitting start on a frozen screw. Stock spare hanger bearings and coupling shafts.

Screw conveyor parts Hanger bearings

Reducer oilCheck thisBefore the freeze

Check: Every outdoor gearbox against its nameplate and manual. Vents clear of snow.

Between -10 and -30 F: Dodge TIGEAR-2 calls for its low-temperature lubricant (part 334861 quart, 334860 gallon). Don't mix it with the factory fill.

Colder than -30 F: Dodge says to contact its engineering team before running TIGEAR-2 reducers.

Dodge TIGEAR-2 standard oil covers down to -10 F for a properly service-factored reducer.

Fix: Pour point is not a safe-start temperature: oil stops flowing well before it. A soft starter takes the shock out of cold starts, but deice first.

Shaft-mount reducers Soft starters

Patrols, deicer and walkwaysCheck thisEvery shift

Check: Exposed belts every shift once it stays below freezing, twice a shift in the deepest cold.

Fix: Keep deicer, sand or floor-dry on hand. Sand walkways and keep three points of contact on ladders.

LOTOLockout before clearing iceCheck thisEvery time

Check: Lockout at the disconnect, not the start/stop controls, which do not cut the power conductors. Test that power is off.

Fix: Block the belt in both directions and relieve take-up tension, because stored energy can remain. Never clear ice from a running conveyor.

LOTOevery time

Clearing ice is when people get hurt

In 1997 a miner was killed thawing frozen mud at a conveyor tail pulley with a propane burner. The guard was off and the conveyor was not locked out (MSHA).

Lock out at the disconnect, test it, block the belt both ways and relieve take-up tension before anyone touches ice.

Need the belt itself?