How to choose a rack for mixed cable drum sizes from Ø737–2007 mm

Plants processing mixed drum families usually lose time at the same point: diameter changes force a new storage rule, a new picking path, or a new rack. A better approach is to treat the rack as an adjustable system. In the Carack layout, the support bracket sits on a perforated stand, and the roller seat can be repositioned in 100 mm increments. This allows one frame series to accommodate drums from approximately Ø737 to Ø2007 mm without building a separate rack line for each diameter.

Group drums by diameter range, then assign the level

Start with two ranges instead of a long list. Larger drums belong on the lower level because they are heavier to lift, create a lower center of gravity, and require clearer forklift access. Smaller drums can go on the upper level if the shaft line hits the support rollers cleanly. In practice, one support pair should be treated as one drum seat unless the project contract specifies otherwise. This keeps the load path simple and prevents the rack from becoming a custom puzzle at every retrieval point.

Set support spacing to the drum centerline, not the catalog size

The usable number is not a rack size. It is the support line height relative to the drum centerline. The 100 mm spacing matters because it allows small corrections without changing the entire frame. For a plant with mixed drums, this means the same stand can be tuned for different core heights while the roller bracket keeps the contact surface aligned. The close-up photo of the bracket shows the bolted roller assembly: two metal rollers, heavy mounting bolts, and a blue stand. That is the mechanical reason why the rack is adjustable without a fixed cradle.

Lower level for heavy drums, upper for lighter ones

With mixed Ø737–2007 mm inventory, the lower level should carry the largest and heaviest drums, as this is safer for handling and easier to access with a forklift or lift truck. The upper level should not be treated as extra storage at all costs. It is the level for drums that can be lifted, rotated, and set back without forcing the operator into awkward reaches. This is where the structure from the aisle photo matters: the stiffened frame keeps the field rigid while multiple drum sizes sit in a continuous row.

What does the auxiliary field actually deliver?

An auxiliary field increases density when it removes duplication. If each drum diameter gets its own isolated rack line, the plant pays twice: once for steel and once for aisle space. A main frame with auxiliary fields combines sizes in an organized track, so the density gain comes from reducing dead gaps and redundant aisles. The exact increase is not a catalog number. It depends on the drum mix, aisle width, and how many diameters can share the same support logic. That is why the final level count and load limit must still be defined in the technical contract, not taken from a general brochure.

Where this layout fits and where it does not

This layout is well suited when the plant has mixed drum sizes, frequent movement, and the need to keep storage in one aisle. It is not the right choice when each drum family must be stored in a separate certified cell, when core width is highly irregular, or when outdoor exposure requires a corrosion protection package that has not been approved. In these cases, the frame concept remains the same, but coating, anchoring, and level count must be rechecked before release.

Planning checklist for a rack with mixed drums

• Confirm the drum diameter range and group the sizes before setting the level height.
• Use 100 mm support adjustments to match the drum centerline instead of forcing a fixed cradle.
• Place the heaviest drums on the lower level and keep forklift access clear.
• Let auxiliary fields increase density by removing duplicate rack lines, not by overloading a field.

FAQ

How many drums should I place on one level?

There is no safe universal answer. A conservative layout treats one support pair as one drum seat and then checks whether smaller drums can share the same field after the centerline and spacing are verified. The final count must follow the project contract.

Is the 100 mm support spacing a fixed catalog promise?

No. It is a practical adjustment method. The spacing gives the installer leeway to align the rollers to different drum geometries, but the final setting still depends on the drum diameter, core width, and handling method defined for the project.