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Superflat Very Narrow Aisle Warehouse Floors

Superflat Very Narrow Aisle Warehouse Floors

Very Narrow Aisle (VNA) Warehouse

For floor profile measurement purposes, all floors naturally divide themselves into two broad categories: Defined Traffic and Random Traffic.

Defined Traffic floors are those on which all vehicular traffic will be constrained by rails or guide wires to follow pre-determined, fixed wheel tracks.

Defined Traffic floors are installed in Very Narrow Aisle warehouses serviced by turret trucks. Operational efficiency in this type of warehousing is determined by the number of pallets handeled per truck per hour – which ratio is determined in large part by the flatness/levelness of the wheel tracks in which the lift truck wheels must roll.

Turret truck manufacturers strive to achieve higher truck speeds, increase truck stability and reach greater rack heights to increase productivity. Without a flat and level floor on which to run, however, these efforts are worthless.

If the floor is too bumpy, the truck will shake too much and the driver won't drive the truck at top speed. More trucks will be needed to move the same number of pallets, and the anticipated advantages of the warehouse will be diminished.

Floor Flatness Issues in High-Speed VNA Warehouses

Any Very Narrow Aisle warehouse floor needs to be three to four times flatter than conventional concrete floors. Therefore upon floor installation, the flatness and levelness in the future lift truck wheel tracks need to be corrected in order to improve truck rideability. There are two usual methods to address this problem: to install a self-levelling overlay (1) or to grind the high spots (2).

However, when the operation of the warehouse requires high lift truck speed (9-10 km/h) and the aisles are above 60 meter of length, even skilled contractors have difficulties to provide the desired flatness and levelness requirements, and the owner usually has to compromise as to speed and riding comfort, in other words efficiency.

Corrective Grinding of Very Narrow Aisles

Fmin Floor Tolerances

By utilizing the Fmin Floor Profile Tolerance System and its testing with the D-Meter(R), even extraordinary flatness/levelness results can be consistently attained, thus allowing smooth and uninterrupted warehousing operations.

The Fmin System is a Defined Traffic floor profile definition system that controls all lift truck motions including the side-to-side and front-to-back tilts, angular velocities and angular accelerations to be experienced by a hard-axle vehicle of known wheel configuration travelling along its intended wheel tracks.

Fmin is a Vehicle Simulation System that controls both the statics and dynamics of the lift truck at all locations within the aisle.

D-Meter(R) Testing of Lift Truck Wheel Tracks

Fmin tolerances have been traditionally measured with the Face Floor Profileograph (or one of the several derivatives), invented in 1979 by Allen Face and his father. Until 2005 this was the only instrument capable of providing the necessary composite wheel track readings and Fmin testing was monopolized by specialty testing firms (this is still the case in Europe and the Eastern hemisphere). In 2005 the D-Meter(R)'s software package was ammended to perform the Fmin requisite calculations. The D-Meter(R) Walking Floor Profiler requires no special skills or training to operate. This allows any company to measure Fmin with its own equipment and personnel and eliminates the cost of hiring specialty testing agencies.

Corrective Grinding of Very Narrow Aisles

Floor Profile Control with D-Meter(R)


Therefore the Fmin System coupled with the D-Meter(R) offers the possibility to any flooring company equipped with hand grinders and plenetary grinding machines to achieve satisfactory flatness/levelness results in Very Narrow Aisle warehouses and permits the owner to realize significant economies.

Please see below two examples of what this powerful floor profile control system is capable of.

Project #1

Aisle length:78 meter
Rack height: 12 meter
Turret truck: Still MX-X
Fmin requirement: 100 (translates to transverse levelness 2 mm, longitudinal levelness 2,4 mm, longitudinal flatness 0,8 mm)

Floor Profile in the Wheel Tracks Before Corrective Grinding - Fmin30

Floor's Profile in the Wheel Tracks after Corrective Grinding - Fmin100 = Superflat

Project #2

Aisle length:63 meter
Rack height: 12 meter
Turret truck: Still MX-X
Fmin requirement: 80 (translates to transverse levelness 2,4 mm, longitudinal levelness 2,9 mm, longitudinal flatness 1 mm)

Floor's Profile in the Wheel Tracks after Corrective Grinding - Fmin80

Floor's Profile in the Wheel Tracks after Corrective Grinding - Fmin80

How Do I Know what Fmin Number to Specify/Require?

Fmin Recommendations

In order to ensure the success of corrective grinding in Very Narrow Aisle warehouses, the owner is strongly advised to retain the services of an expert defined traffic concrete floor consultant.

Allen Face Europe - The Defined Traffic Floor Expert

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