Pallet Racking FAQ: 239 Questions, Answered

A 42-inch-deep frame with 96-inch beams holds two 48-by-40 pallets per level, 40-inch face out. That leaves 16 inches to split between the two ends and the middle. A centered pallet overhangs three inches front and back. Three pallets per level needs a longer beam, often 144 inches, sized to your loads. Frame height comes from your clear height, sprinklers and forklift.

It depends on the maker, length, face height and gauge. Every beam pair has a maker's rating. We give you the rating for the exact beam we quote. A tall first level can need a heavier upright.

Set by the truck: sit-down counterbalance 12 to 13 feet, stand-up reach 9 to 10, deep-reach 10 to 11, guided VNA 5.5 to 6.5. Check whether the dealer's right-angle stack figure already includes clearance.

Not for good pallets on 42-inch frames. Use it for loose cases and odd pallets; many insurers and fire marshals ask for it. Mesh, not solid sheet, so sprinkler water gets through.

Often, yes. The height that triggers it depends on your town. Tall combustible storage can also need a separate fire permit and a sprinkler review. We check your address and file stamped drawings and seismic calculations where required.

Teardrop parts from many makers fit together, but a fit is not a rating. Mixed parts need an engineer's approval. We identify the make, confirm capacities and keep structural and roll-formed separate.

Close enough that the load does not sag. It depends on how stiff the material is and how it is bundled. The maker sets the spacing for your material.

Each arm is rated for an even load along it. The column and base have their own ratings, so adding up the arms does not rate the column. Weight at the tip lowers the arm rating.

Single-sided stands against a wall. Double-sided puts arms on both sides of one column line. It needs more depth and an aisle on each side.

A counterbalance forklift turning with 16-foot stock usually needs 15 feet or more; a side loader works much narrower.

Most towns want a permit over eight feet, and outdoor racks may need wind and frost checks. We handle the filing. Used structural cantilever saves money if columns, arms and bracing are one series.

Two, three and four deep are common. Five and six deep exist, but each added cart raises the load and needs more clearance. Three deep suits most freezer and food operations.

A counterbalance or reach truck with the capacity and lift for the top level. The maker confirms the fit. Push gently and keep the pallet square; a crooked pallet is the usual cause of jams.

Good GMA-style pallets with solid bottom boards. Broken boards hang up; for rough pallets, pallet flow or drive-in may fit better.

Push-back for many SKUs with a few pallets each; it costs more per position. Drive-in for a few SKUs by the truckload, the most pallets per square foot for less.

The rails slope gently toward the aisle, at the angle the maker sets. We set and test it with loaded pallets at installation. Inspect carts and rails once a year.

As deep as one SKU and date code fills in a reasonable time. Three to six deep is typical for food and beverage; ten deep for a plant that makes one product. Very deep lanes slow loading.

Usually a counterbalance or reach truck. Lanes are sized to the truck, so send the model before the layout.

The pallet rests on its edges on two rails, set for the pallet the system is designed around. Pallets must be sound. Odd or mixed pallets need another system.

In the order set in the maker's operating manual. Keep one SKU and one date range per lane.

Yes, it is the most common freezer rack. Galvanized rails resist corrosion and the floor must be flat. Ice on rails and floor needs a regular cleaning and inspection routine.

About three-eighths to a half inch of drop per foot, roughly two degrees. The maker sets it for your pallets. Heavy pallets need less, light ones more.

Solid, straight bottom boards roll best; broken boards, soft plastic pallets and leaning loads stop. Full-width rollers forgive the most. Bring a sample pallet and we run it.

Two to twenty deep, most four to ten. The maker sets the speed controllers and stops for your pallet weight, slope and depth.

Stop and call a trained person. The pallets behind it are held back by gravity, so clearing a lane follows the maker's procedure. Worn rollers, bent stops and bad pallets cause hang-ups.

Both are first in, first out. Pallet flow is faster and easier on the rack, for pick faces and high turns. Drive-through costs less per position and takes rough pallets, for bulk dated goods.

Often yes, if the frames and beams are rated for the loads. We add a second row, tie it with row spacers and adjust beam levels.

A double-reach (deep-reach) truck.

Push-back uses nested carts and a counterbalance truck and goes deeper. Double-deep uses standard beams and a double-reach truck and costs less per position.

Drive-in for maximum density. Drive-through when the oldest pallet must leave first.

Sometimes, if the back is not against a wall and the bracing can be re-engineered.

Four to eight pallets is common. Deeper lanes hold more but are slower to work.

Five to six feet for most turret trucks.

Some pass, some need grinding along the aisles, a few need a new topping. We survey first.

It can, in a rack-supported building designed that way from the start. The rack, building and anchors are engineered together. Existing selective rack cannot simply take a roof.

A step beam has a ledge so decks and supports sit flush. A box beam is a closed tube and needs clips or support bars for decking.

It depends on the maker, gauge, connector and length, not size alone. Use the maker's load chart for that beam, per pair, load spread evenly.

Only if the connector matches and an engineer approves the mixed set. A fit alone does not prove the rating.

So a forklift cannot lift the beam out from below. ANSI MH16.1 and most insurers require them.

Depth: 42 inches for a 48 x 40 pallet loaded 48-inch side in. Height: pallet heights plus 6 inches per level, under the truck's lift and the sprinkler limit.

It depends on the maker, column size, gauge and beam spacing. Use the maker's capacity chart for your frame.

Teardrop costs less and suits most warehouses. Structural takes more abuse, for freezers, food plants and rough forklift traffic.

Unload it and have a qualified person assess it. They decide repair or replace. An approved repair kit often costs less than a new frame.

Not for good pallets on a 42-inch frame. Yes for hand-stacked cases, totes and odd shapes, and where the fire marshal or insurer asks. Broken pallets come out of service.

A 42-inch frame with 96-inch beams takes two 42 x 46 decks; 108-inch beams take two 42 x 52. Waterfall on step beams, flush with clips on box beams.

The maker's label gives it for that size and channel layout, load spread evenly. Pallet runners and point loads need their own rating. The beam pair still sets the level limit.

For most loads, yes. Supports are cheaper for good pallets with nothing loose.

12 inches is common. With 3 inches of overhang at the back of each pallet, it leaves a 6-inch gap between loads. Your fire design sets the gap you need.

As many as the maker's or engineer's spacer schedule calls for. Taller frames get more.

ANSI MH16.1 expects back-to-back rows tied, and the fire design sets the flue. Inspectors check.

No. A beam is not rated for sideways load and blocks the flue.

Yes. The rack standard requires every upright column anchored, and inspectors check.

Whatever the rack maker or engineer specifies for your frames and slab. Tall, heavy or seismic jobs get bigger anchors, deeper embedment and more per plate.

Yes, after scanning so holes miss the lines, sometimes with adhesive anchors. Tell us before install.

Shims keep the column plumb, within the maker's shim limits. Past those limits, the engineer needs to know.

It depends on the pallet, the load and the bar rating. Use the maker's chart; drums and heavy loads need an approved layout.

Supports cost much less. Use decks if anything loose goes on the level or the insurer asks.

Drop-in supports fit step beams with a matching step. Box and structural beams need clip-on or bolt-on. Send a photo of the beam end.

No. The beam pair's rating still sets the limit for the level.

Cases load at the high back and roll to the low front, so the oldest case in each lane comes out first. That holds when lanes are loaded from the back.

About three-quarters to one inch per foot; more for light cartons, totes and soft bottoms. We set each lane on site.

Usually yes. Beds hang on standard step beams. The bay needs a way to load from the back or front.

Pallet flow moves pallets on heavy rollers by forklift. Carton flow moves cases and totes on wheels by hand.

Standard columns run 8 to 24 feet; structural goes higher for coil and plate.

Single sided against a wall. Double sided in open floor, serving two aisles.

So product rests on at least two arms without sagging. The maker's spacing chart for your material sets it.

Structural is hot-rolled I-beam for forklift-loaded lumber, steel and pipe. Roll-formed is lighter, for hand-loaded furniture and carpet.

Straight for lumber and boxed goods. Inclined for pipe, tube, bar and rolls.

It depends on the arm length, section and maker. Use the maker's chart, per arm, load spread evenly.

As long as the product is deep: 36 or 48 inch for lumber and pipe, 48 for sheet goods, 24 for furniture.

Yes, if they match the slot pattern and the column has capacity. Send a photo of the column and any maker's tag.

Longer than the arm. The maker's drawing gives the length for your arm and load.

Yes. Outdoor racks on asphalt need concrete pads or piers.

Yes, centered and inside the base ends.

Match the columns: double for double-sided, single for single-sided.

Yes. Without diagonals a loaded row leans and can fall.

The engineer's drawing gives the count. Taller rows and seismic areas get more.

No. A row missing a diagonal is out of service until it is back.

Rarely; they fit one column spacing and section.

Both hold two pallets per level. Double-deep needs a deep-reach truck; push-back rolls the back pallet forward for any truck.

Two per lane per level, so 8 in a lane 4 levels high. A 96-inch bay usually holds two lanes of 40-inch-wide pallets.

Often yes. We check frame depth, beam capacity and floor slope first.

About 12 1/2 to 13 feet.

About three-eighths to a half inch per foot, roughly 6 inches over a 3-deep lane.

Last in, first out.

Each lane and level can hold its own SKU, and the truck stays out of the rack. Loading can be faster, depending on the layout.

Four per lane per level. One lane 4 levels high holds 16; a two-lane bay holds 32, so ten bays hold 320.

Often, when SKUs fill whole lanes: a SKU per lane and level, and no truck in the rack. Drive-in can cost less per position.

Five and six deep exist, with lanes of 20 feet and more. Past 4 deep, drive-in or pallet flow is usually better.

Not a deep-reach truck. It must reach the top level and have the capacity and push the maker specifies.

Five per lane per level. A 4-level lane holds 20; ten bays of two lanes hold 400.

For most, yes: a SKU per lane and level, no truck in the rack. Drive-in is cheaper per position and goes deeper.

No, if it reaches the top level and can push four loaded pallets.

No. Common systems run two to six deep, depending on the maker. Past that, pallet flow or a pallet shuttle.

Teardrop: inverted teardrop slots, beam pins drop in, no bolts. Interlake Mecalux, Steel King, Husky and most others build it.

Often they fit. Slot shape and spacing match, but column steel thickness, width and pin size vary, so fit can be loose or tight. Fit is not a rating: a mixed row needs an engineer's approval. We check fit on every used teardrop lot.

Teardrop has two columns of inverted teardrop slots. Keystone has one column of trapezoid holes down the middle of the face, and the beam hooks in instead of pinning.

A roll-formed rack with rectangular slots and a raised ridge down the upright face. Hooked beam flanges rest on the ridge, held by a spring lock in the column. Still made.

Yes. Send a straight-on photo of the column face with a tape measure across it, plus a beam end. We reply the same day with the style, what fits and what we stock.

Often, but compare the rated charts: section, gauge, steel, connector and span decide capacity. Structural usually survives hits that dent or tear roll-formed. For ordinary pallets and careful drivers, roll-formed is plenty and costs far less.

Material costs noticeably more at the same bay size, and installation takes longer because every beam is bolted. Used structural, when we have it, closes most of that gap.

Yes, where the maker punches structural columns with teardrop slots so roll-formed beams drop in. Popular for cold storage and busy aisles.

Structural, or structural uprights with roll-formed beams. Freezer racks get hit more (gloves, fog, speed) and repairs there are expensive.

A step beam has a step on the inside top edge that wire decks and pallet supports drop into. A box beam is a closed rectangle and needs decks that sit on top.

No, the channels have nothing to sit in. Box beams take U-channel (inverted) or universal decks that rest on top.

The structural rack beam: a hot-rolled channel bolted to the column with two bolts through a welded angle bracket on each end. It often outcarries a rolled beam of the same height and takes forklift hits better. The chart has the rating.

It depends on the length, the section, the steel and the connector. Face height or beam shape alone does not tell you. The exact figure is on the maker's chart, which we supply with every beam.

Length between the connector plates, face height of the front wall, and step or box. Photograph the connector to identify the style.

42 inches. The pallet overhangs 3 inches front and back, which keeps the load on the beams.

Pallet height plus about 6 inches of lift clearance plus the beam face: about 58 inches for a 48 inch load on a 4 inch beam. Frame capacity depends on this spacing.

A starter is a complete bay with two uprights and beams. An adder adds one upright and beams, sharing the other upright with the bay beside it. A row of 10 bays is 1 starter and 9 adders: 11 uprights.

A 96 inch beam on 42 inch uprights, holding two 48 by 40 inch pallets per level with 3 inches of overhang front and back. 12, 16 and 20 foot uprights cover most buildings.

Beam length plus one 3 inch column: a 96 inch beam makes a 99 inch bay centre to centre, a 108 inch beam a 111 inch bay. Ten 96 inch bays run 82 feet 9 inches.

Load height plus about 6 inches of lift clearance plus the beam face. A 48 inch load on a 4 inch beam puts levels about 58 inches apart.

Two 46 inch wide decks per bay, as deep as the frame; 42 by 46 is standard. 108 inch beams take 52 inch decks, 120 inch beams 58 inch.

12 to 13 feet for a sit-down counterbalance, 8.5 to 10 feet for a reach truck, 5.5 to 6.5 feet for a guided turret truck: the maker's right-angle stacking aisle, plus 6 to 12 inches if that figure does not already include clearance.

The width a truck needs to turn 90 degrees into a bay with a 48 inch pallet and back out. It is on the truck's spec sheet.

OSHA requires aisles wide enough for equipment to pass safely and sets minimums for exit routes. Building and fire codes can require more, depending on how many people use the route. In practice no truck stacks in less than about 5 feet, and most need 8 or more.

With 8 foot back-to-back rows, 6 foot aisles fit about 40% more positions than 12 foot counterbalance aisles. The cost is the turret truck, guidance and tighter install.

Base it on how hard the rack is used. A program we suggest: a daily look by drivers, a documented monthly inspection by a trained person, and an expert inspection yearly and after any significant hit. Keep a record.

When a qualified person who has assessed it says so. Bent, creased or torn columns, missing or cracked bracing, and failed footplates or anchors all need that assessment. Unload and tag the bay until it is replaced or repaired with an engineered kit.

Yes. RMI, most fire marshals and insurers require a plaque per row with beam, bay and frame capacities at the installed spacing. We supply them with every install and inspection.

Not in place; cold-straightening weakens the steel. Replace the frame, or use a manufacturer-engineered repair kit approved by the engineer.

Per pair, almost always, with the load spread evenly. A 4,500 pound rating means two beams together carry 4,500 pounds. A few makers quote per beam, so check.

The beams brace the column; the longer the unbraced length, the less it carries before buckling. Moving beams changes the rating.

It depends on the beam and frame sections, the beam spacing and the maker. The maker's charts give the numbers, and the load plaque states them for your installed rack.

The sign on each row stating beam, bay and frame capacities at the installed spacing. Insurers and fire marshals check it first.

Yes. Used racking and mezzanines finance on the same programs as new, including installation and freight.

It depends on the lender and the project size. Smaller projects can often be decided on the application alone; larger ones that need financials take longer.

Established businesses with reasonable credit get the best rates. Newer businesses and past credit issues still have programs, usually with a larger first payment or shorter term.

An equipment finance agreement or $1-buyout lease suits equipment you keep: you own it. A fair-market-value lease has the lowest payment, for equipment you will replace or return. Racking is usually kept, so most customers pick the $1 buyout. Ask your tax adviser how each one is treated.

Qualified buyers can finance 100 percent of the project. The first payment, fees and taxes may still be due at signing. Newer-business programs may ask for payments up front.

It depends on the program. Ask how an early payoff is figured; some keep part of the finance charge. The quote states it.

Yes, for a project we quote.

Building size, clear height, a floor plan or photos, pallet size and weight, and your forklift type. No drawings? We measure.

Depends on job size and season. Give us your dates.

Yes. Send the material list and we quote the labor.

Yes. You get a certificate of insurance first.

In many towns, yes for tall rack (often over 8 or 12 feet, set by the town), any rack in a high seismic area, and any mezzanine. Over 500 square feet of storage above 12 feet also needs a high-piled storage fire permit. We check your address before you order.

Combustible storage over 12 feet high (6 feet for plastics, tires, aerosols and other high-hazard goods). Over 500 square feet of it triggers a fire permit and a review of sprinklers, flues, aisles and access.

Often, yes. We survey it and have it engineered as built.

Drawings take one to two weeks once the layout is final. Review is days in some towns, four to eight weeks in busy ones.

Typically $1,500 to $5,000 for a racking job; mezzanines cost more. Permit fees are the town's. Sprinkler changes are the big variable.

Yes, same as new. We identify and rate the parts.

Depends on type, condition, quantity and access. Send photos and a count.

Yes. For a few bays, our Goshen yard may be simplest.

No, we do the teardown.

Give us your date and building size and we commit to a schedule.

Yes, every week from our 18-acre yard in Goshen, NY. Used stock usually ships within days; standard new sizes are in stock or short lead time.

Yes. We install with the delivery, nights and weekends if needed, after the permit and engineering.

Yes. Send photos and a count. We quote, take it down and haul it, usually within the week.

Used stock usually arrives within days from Albany to Long Island, often next day in the Hudson Valley. Standard new sizes are in stock or short lead time.

Yes. Our engineer stamps the drawings and high-piled storage report, we file with the Department of Buildings and the Fire Department, and install after approval.

Yes, every week from our 18-acre yard in Goshen, NY. Used stock usually ships within days; standard new sizes are in stock or short lead time.

Yes. We install with the delivery, nights and weekends if needed, after the permit and engineering.

Yes. Send photos and a count. We quote, take it down and haul it, usually within the week.

Every week, often several times. Used stock reaches Northern and Central Jersey within days; South Jersey runs are grouped to keep freight low.

Yes. We work nights and weekends around building security, dock schedules and union rules.

Yes, every week from our 18-acre yard in Goshen, NY. Used stock usually ships within days; standard new sizes are in stock or short lead time.

Yes. We install with the delivery, nights and weekends if needed, after the permit and engineering.

Yes. Send photos and a count. We quote, take it down and haul it, usually within the week.

Used stock ships within days. Hartford and eastern Connecticut go on weekly trips.

Yes. A Connecticut-licensed engineer seals the drawings and calculations, and we file with the town and fire marshal.

Yes, every week from our 18-acre yard in Goshen, NY. Used stock usually ships within days; standard new sizes are in stock or short lead time.

Yes. We install with the delivery, nights and weekends if needed, after the permit and engineering.

Yes. Send photos and a count. We quote, take it down and haul it, usually within the week.

Yes, every week. Used stock is usually installed within days.

Yes: selective, push-back and pallet flow, pick modules and rack-supported mezzanines, with engineering and the UCC permit done first.

Yes, anywhere in the United States. Freight and travel are lines on the quote.

Yes, by the truckload from our 18-acre yard in Goshen, NY. For far jobs, new racking direct from the factory often lands lower.

Yes. An engineer licensed in that state seals the drawings and we file locally.

About eight feet clear below (ten to twelve for forklifts), 14 to 18 inches for the floor structure (beams, joists and deck), and seven to eight feet on top. 20 feet clear is tight; 24 feet is comfortable.

The engineer rates it for your use. Storage decks are designed heavier than office decks, and pallet jacks or equipment add point loads that are checked separately. Columns often need a footing.

Free-standing when the space below must stay open. Rack-supported when pallet rack below carries the deck. Shelving-supported when both levels are shelving.

A forklift through a safety gate, a vertical reciprocating conveyor, or an incline conveyor. The gate is cheapest for a few pallets an hour.

For 2,000 to 5,000 square feet free-standing: a few weeks to engineer and permit, six to ten to deliver, a week to install.

Two or three is most common, limited by building height and sprinklers. Each level needs about ten feet.

Not always. Small modules use carts and a lift or chute. At higher volumes a conveyor can pay off. We run the numbers on your volume.

Often yes. Carton flow shelves drop onto standard beams.

It needs engineering, a permit and usually in-rack sprinklers. We handle drawings, stamps and inspection.

Catwalk when the upper level is shelving only. Mezzanine when the floor above holds pallets, offices or machines.

Often, if the posts can go full height and the brand makes a catwalk system.

Usually not as is. Frames and often beams get replaced or added to. We survey it first.

Rack-supported when the space below stays racking. Free-standing when it must be open or may change use.

No. A mobile racking block or one shuttle aisle can pay off in a mid-sized freezer or tight plant.

Often. Mobile racking and shuttle systems fit under most roofs; AS/RS cranes need height, so they suit new buildings or high-bay additions.

The manufacturer services the equipment. We maintain and inspect the racking.

The operator commands it by remote. Battery life depends on the model, duty and temperature.

Sized to lane count and pallets per hour.

Same density. Shuttle is deeper and faster; drive-in costs less.

Yes, with an aisle at each end. With one aisle it runs last in, first out.

Recovery follows the maker's procedure. Trained people do it, with the lane made safe first.

Very tall. The crane model, building, floor and fire code set the limit.

Tolerance. The crane places a pallet to within an inch at height, so the rack is built to a much tighter spec.

Usually as a high-bay addition. Low buildings rarely work.

Tote shuttles have much higher throughput. Miniloads cost less and suit lower volumes.

Commonly 30 to 60 feet, so bracing, floor flatness and seismic design matter.

Same lanes, plus a lift, carriers and conveyors.

Sometimes, if the rack is straight enough and there is room for the lift and conveyors.

It depends on the rows, aisles, staging and fire design. We show the count on your layout.

It depends on the aisle width and base speed. The maker gives the time for your layout.

Sometimes. The maker and an engineer must approve it for the bases, loads, slab and fire design.

Rollers for solid bottom boards; chain for stringers, odd sizes or broken bottoms.

Yes, usually to a pick-and-drop station at the aisle end.

Boltless (rivet) goes together with a mallet, for light parts. Clip shelving is for small parts and bins. Long-span has particleboard or wire decks for bulky items like cases, tires and totes.

It depends on the model, shelf size and reinforcement. Ask for the maker's rating. The unit also has its own total, so shelf ratings do not simply add up.

Anchor or tie any unit taller than it is wide, and tie rows together at the top. Seismic areas require it.

Yes, clip and boltless are the most common items in our yard. Sold as complete units, because mixed makes do not fit.

Gravity runs on a slight slope with no power, for docks and packing. Powered runs level or uphill at a set speed, for lines that merge, sort or feed a machine.

Width comes from your widest carton, how it sits on the line and the frame style. We size it from the maker's table. Keep three rollers under the shortest carton.

About half an inch of drop per foot, a little more for light cartons. Past about 30 feet cartons speed up, so add a brake roller or a flat section.

Yes: a lift gate for people, a bridge for forklifts, or a guarded floor-level section.

Gravity, skate-wheel, legs, curves and flex come through our yard often, sold by the section. Powered is usually new, because drives and controls must match the line.

About three-eighths of an inch per foot for cardboard cartons, more for light cartons and totes, less for heavy flat loads.

Carton width plus about two inches, with three rollers under the shortest carton. Measure the widest carton across the conveyor, not its length.

It depends on the roller, axle and support spacing. Use the maker's chart for the model.

Yes, with closer roller centers and a bit more slope. Skate wheel is often better.

Skate wheel for cartons and totes at docks and on temporary lines. Roller for heavy loads, drums, bags and uneven bottoms.

It depends on the wheels, frame and support spacing; use the maker's chart. Flat-bottomed loads on at least three rows of wheels.

Yes. Aluminum sections are light enough for one person.

About 6 feet closed to 24 feet open per unit; units join end to end and bend 90 degrees or more.

It depends on the model and how far it is extended; use the maker's chart. Cartons and totes, not pallets.

No. A powered version handles slopes and heavy cartons.

Line-shaft runs every roller from one motor all the time. MDR has a 24-volt motor roller per zone, and zones can be set to run only when a carton is there.

Most lines run 60 to 120 feet per minute, up to about 200 with variable-speed drives.

Rollers slip past about 5 degrees. Use a belt section; flat-bottomed cartons climb 10 to 15 degrees on belt.

Not a simple transport line. MDR cards handle simple logic; a small PLC runs merges and sorting.

Belt for small or soft items, scanners, scales, inclines and quiet areas. Roller for accumulation, heavy loads, and dirty or wet areas.

About 20 degrees plain, 30 to 35 with cleats, for ordinary cartons. Steeper needs a special sidewall belt, a spiral or a vertical lift.

Slider bed up to about 50 pounds per foot. Roller bed for heavier loads and long runs.

Years in normal warehouse use. We stock belts and re-lace or replace them on site.

Cartons queue without line pressure, so fewer crushed cartons. How well it works depends on the sensors, controls and setup.

The longest carton plus a few inches: 24 or 30 inches for most mixes.

Not for a straight line. Add one for merges, diverts, scanners or a sorter.

Singulation releases one carton at a time, for scanners and labelers. Slug releases the whole queue, for a sorter or pack station.

Check the maker's curve table for your longest and widest carton. Roller taper and guide rails matter too.

A photo-eye or scanner identifies the carton, then angled wheels or a belt push it onto the side line. The rate depends on carton size, gap and controls.

Yes, with a spur at 30 or 45 degrees and a merge zone that alternates cartons.

Through a spring-assisted gate that lifts with one hand.