Why not cut five holes into one solid block of foam?

Solid foam leaves 8 mm between pockets, and a 4.5 kg host dropped from 1 m crushes that web; separate 12 mm blocks are replaced one at a time.

Would a 250 mm drum not save space?

It saves 100 mm of width and costs 1.4 extra turns, 6 s more per pull, and a hose end gloves cannot catch. A 560 mm shell still clears a tower door.

Can the couplant share the host bay?

No. A litre seeping sideways soaks the floor, and the gel moulds open-cell foam from inside.

Will the lid open at -20 °C?

With a -30 °C gasket, yes. Seals sit at 25 percent compression and opening force is 60 N, while two gloved hands exceed 80 N. At room temperature it drops to 45 N.

Is 11.8 kg sensible on a ladder?

Up to 15 kg works with the back panel: 15 mm of panel and 50 mm straps carry a 30 m climb without a shoulder change.

Blade Inspection Case

Quick answer: A blade inspection case splits 560 × 400 × 250 mm into five bays, so a 4.5 kg host, six probes and a 1 L couplant bottle travel at 11.8 kg.

Why the bays come before the foam
Host bay and probe slots
Coiling: 3 m of hose on a 400 mm drum
Couplant: a one litre bottle in its own bay
Cold starts, one-hand carry and ladder work
FAQ

1. Why the bays come before the foam

A 4.5 kg flaw detector, three metres of 6 mm probe hose and a litre of couplant share nothing but the trip. The host fails at a corner drop from 1 m. The hose fails where it kinks, leaving a white crease in the jacket. The couplant fails by leaking, and one leak ruins a foam block.

The lazy layout is one open cavity with the coil beside the host, all inside 560 × 400 × 250 mm. Retrieval breaks it: the hose sits underneath, so every job starts with 40 s of dragging it free.

Five bays give the host a floor of its own, six vertical probe slots, a drum bay, a bottle bay and one for adapters. The path becomes open the lid.

Box layout	Bays	Hose kinks per trip	Moves to reach the host	Loaded weight
Single cavity	1	2	4	10.6 kg
Host plus hose	2	1	3	11.2 kg
Five bays	5	0	1	11.8 kg
Six bays with bottle bay	6	0	1	12.1 kg

2. Host bay and probe slots

The host bay is 260 × 200 × 120 mm with 10 mm of EPE, screen up, connector to the opening. Another 3 mm clears the screen so lid foam touches only the bezel: the display is 2.5 mm of tempered glass on a 0.3 mm adhesive layer.

Blade inspection case: empty black shell open on grey, lid foam with three rectangular recesses, base foam split into unequal square pockets

Six slots of φ30 × 80 mm take the 6 mm probes, sunk 80 mm. Standing protects the root: the probe-to-hose transition is 25 mm long, and flat storage bends it through 90°, while eight swaps a day shows wrinkling within a month.

Walls run 12 mm with a 2 mm chamfer, so a gloved finger can pinch the tail without picking at it.

3. Coiling: 3 m of hose on a 400 mm drum

A 6 mm hose takes a 60 mm bend radius at ten times its diameter, so a 130 mm drum would do, yet this one is 400 mm. Retrieval sets it: 3.8 turns on a 250 mm drum means rotating the wrist through nearly four turns while pulling, impossible in cut-resistant gloves, while 2.4 turns slide off in one pull.

The arithmetic checks: 1.26 m per turn at 400 mm times 2.4 gives 3.02 m for a three metre hose. The wall is 2.5 mm and the face 40 mm with 8 mm flanges; 2.4 turns use only 15 mm of it.

The exit keeps a 40 mm free length under a 3 mm clamp; eight flexes a day, spread over an 8 mm radius, push jacket fatigue past 10,000 cycles.

Drum diameter	Turns for 3 m	One-hand pull	Face width used	Shell width
250 mm	3.8 turns	12 s	24 mm	460 mm
320 mm	3.0 turns	9 s	20 mm	490 mm
400 mm	2.4 turns	6 s	15 mm	560 mm
500 mm	1.9 turns	6 s	12 mm	640 mm

4. Couplant: a one litre bottle in its own bay

The bottle is φ90 × 180 mm at 1 L and sits cap-up in a 2 L bay on a 20 mm pad of 40 g felt, 12 mm clear of each wall.

Blade inspection case: open shell with egg-crate lid foam, a meter with LCD set in the base foam, coiled cables and green red probes

Leak-free at 30° rests on a 3 mm cap gasket, the 12 mm walls and the pad. Fill to 1 L, tilt 30° for 2 hours, invert for 2 more, then weigh the pad: under 2 g passes.

The pad holds 60 mL, one cap working loose. Couplant is water-based, and once it soaks into open-cell EPE the foam moulds from inside, so the pad is a removable sheet.

Bottle format	Result at 30°	Bay volume	Bay construction	Cleaning
1 L rigid bottle	No seepage	2 L	12 mm walls plus felt	Swap the pad
500 mL pouch	Seeps under load	1.2 L	Needs a rigid sleeve	Wipe the walls
2 L jerrycan	No seepage	3.5 L	Needs a sunken well	Swap the pad
4 × 200 mL bottles	No seepage	1 L	Six round pockets	Wipe each one

5. Cold starts, one-hand carry and ladder work

EPE stiffens about 30 percent at -20 °C and its compression set climbs from 3 to 8 percent, costing 1.5 mm of travel, so northern builds thicken the host bay from 10 mm to 15 mm and add 8 mm of height. A -30 °C gasket seats at 25 percent compression and holds opening force under 60 N.

Loaded weight is 11.8 kg against a 12 kg one-hand ceiling. The handle is rated 25 kg with a 28 mm grip; ladder carry uses two 50 mm straps and a 15 mm panel spreading the load over 0.06 m² of back.

Lid open to host in hand takes 90 s: 8 s for two latches, 3 s to raise, 12 s to lift the host, 20 s for a probe, 25 s to couple.

Carry mode	Weight ceiling	Main load path	Limiting condition
One hand	12 kg	Two ribs at the handle root	Wrist must stay neutral
Both shoulders	18 kg	Back panel and straps	Rear face must be flat
Ladder carry	15 kg	Panel lower edge and waist belt	Both hands stay free
Two people	30 kg	Side handles	Passage wider than 700 mm

Conclusion

Three decisions carry a blade inspection case: five bays keeping a 4.5 kg host, six 6 mm probes and a 1 L bottle apart, a 400 mm drum coiling 3 m in 2.4 turns and releasing in 6 s, and a bottle bay holding 30° without seepage behind a 40 g pad. Get those right and 11.8 kg still moves through a tower at -20 °C on one hand.