Hindustan Scale Company · Est. 1955Wireless crane scales — safe-distance readout

The safest place to read a crane scale is anywhere except under it.

Yet that is where the rigger stands, shift after shift, in most bays in India: beneath five tonnes of steel, looking up at a small display swinging above his head. A Bluetooth crane scale ends that habit. The scale still hangs on the hook and still weighs the load — but it sends the weight to a phone or tablet about 10 metres away, and to a desk indicator, so nobody walks into the fall zone to read it. This article covers why that matters, how the wireless link works, which capacity to choose from 3 t to 50 t, and what changes for the rigger and the clerk on Monday.

CRHBTDJH – Electronic Bluetooth Crane Scale with double J Hook - the HSCo product this paper is about.
The scale hangs on the hook. The rigger reads it from eight metres away, phone in hand, and nobody is under the load.

Why nobody should be reading a dial under a suspended load

The rule is written down. India’s code of practice for the safe use of cranes, IS 13367 (Part 1), says in clause 13.3: “All persons should stand clear of the load being lifted.” The US rules say it twice — 29 CFR 1926.1425 keeps every employee out of the fall zone except those hooking, unhooking or guiding the load, and 29 CFR 1910.179 requires the operator to “avoid carrying loads over people”.

The numbers behind the rule are blunt. The US Bureau of Labor Statistics counted 297 crane-related deaths between 2011 and 2017 — 42 a year — and found that just over half involved the worker being struck by an object; in 79 of those cases the object had fallen from, or been set moving by, the crane. A 2023 peer-reviewed study in Heliyon of 105 hoisting accidents in China found “struck by hoisting load” the single most common type, with 38 cases. In Britain, the Health and Safety Executive’s 2025/26 figures record 126 workers killed across all industries, 21 of them struck by a moving object — the third-largest cause after falls from height and moving vehicles. A 2026 case study in Scientific Reports of an EOT-crane area in a Tamil Nadu factory listed struck-by and crushing from moving hooks and loads first among its seven risks. Four scopes, one direction.

It is not an abstract risk in India. On 21/08/2026 the Times of India reported that two workers died at a Navi Mumbai construction site when a steel beam being lifted by a tower crane fell on them from the sixth floor. And on 07/07/2026, at a container terminal at India’s largest container port, containers toppled by monsoon wind from a vessel stack killed a 19-year-old worker — not a crane lift, but the same physics.

A crane scale whose only display is on the hook body gives a person a reason to be in exactly the wrong place. To read it, the rigger walks under the load — or squints from an angle, guesses, and walks under anyway.

Figure: being struck by the load is the leading way cranes kill — US crane deaths and Chinese hoisting accidents, each with its own scope; British all-industry deaths as a footnote
Two crane studies, two scopes, one direction: the load is what kills. Each bar stands on its own — they are never added together; the British all-industry figure sits below as a footnote because its scope is different.

The rule you cannot obey without a number

Every lifting machine in an Indian factory is covered by section 29 of the Factories Act, 1948. Its safe working load must be plainly marked and never exceeded except for a test, and a competent person must examine it at least every twelve months and keep a register. IS 13367 adds the practical half: clause 17.1.1 says the weight of the load must be “known with reasonable accuracy” before it is lifted — and where the load is still on the truck, the code’s advice is simply to weigh it.

You cannot obey the safe-working-load rule without knowing the weight on the hook. A crane scale is how a foundry, a scrap yard or a steel stockist knows. The only question is where the reader stands.

NIOSH in the US and CCOHS in Canada rank the ways to control a hazard in the same order: eliminate it, substitute it, engineer it out, and only then administrative rules and protective equipment. The top three work, in NIOSH’s words, “without significant human interaction”; administrative controls, as CCOHS puts it, “do not necessarily remove or reduce the hazard”. A “Do not stand under the load” sign is an administrative control. It depends on the rigger remembering it at 3 pm on a hot Thursday. Putting the weight on his phone removes the reason to be there at all. That is an engineering control, and it works whether he remembers or not.

How does a Bluetooth crane scale get the weight to a phone?

Inside the hook body, nothing changes. A die-cast load cell measures the pull; an embedded controller turns it into a stable weight; the jumbo display on the body still shows it, bright enough to read across the bay. What is added is a short-range radio, which sends each reading to whatever is listening within range:

  1. The Hindustan Scale Company (HSCo) Android app on any phone or tablet. The rigger reads one large number in his palm, and the app can store each lift with a time and the scale’s identity.
  2. A remote desktop indicator on the dispatch clerk’s desk — what OIML R 76, the international standard for weighing instruments, calls a “secondary display”. The clerk sees the number the rigger sees, without leaving the office.
  3. A hand-held remote control working the other way, so the rigger can zero and tare the scale without touching it — again from outside the fall zone.

How far is “within range”? HSCo publishes about 10 metres, line of sight, for its CRHBT range. The Bluetooth SIG explains that range is a property of the whole system: transmit power, receiver sensitivity, antenna gain and whatever is in the way. The European radio standard ETSI EN 300 328 caps 2.4 GHz radiated power at 20 dBm — 100 mW — for everyone, so no maker can simply turn it up. Steel racks, the load itself and the crane’s structure all shorten range. Treat 10 metres as indicative and test it where the rigger will stand.

Ten metres is enough. The fall zone is the area beneath the load and a margin around it; 8 metres to the side, phone in hand, is outside it.

Diagram of a Bluetooth crane scale sending the weight to the phone app and desk indicator, the remote control sending zero and tare back, and an empty fall zone
Three readers, one scale: the phone app and the desk indicator receive the weight; the hand-held remote sends zero and tare back. The fall zone stays empty.

Which capacity, and what does it cost?

HSCo’s five Bluetooth crane scales share one build: a heavy-duty die-cast aluminium body, a metal die-cast load cell, 100 % overload protection, a water- and rust-resistant board under a thick powder coat, an extra-bright jumbo display, and at least 40 hours of battery backup.

Model Capacity Typical loads Indicative price, before GST (September 2026)
CRHBT3K 3 t Scrap bundles, dies, pallets ₹17,500
CRHBT5K 5 t Coils, billets, sub-assemblies ₹22,500
CRHBT10K 10 t Heavy plate, castings, machinery on request
CRHBT20K 20 t Ladles, large castings, port cargo on request
CRHBT50K 50 t Shipyard blocks, project cargo ₹68,500

Prices are indicative list prices before GST; the remote desktop indicator is quoted on request. The wider family is on the crane scale page, and the case for the 5-tonne class is made in the role of 5-ton crane scales in modern industry.

Dispatch clerk reading the crane-scale weight on a remote desktop indicator at her desk beside the bay
The same number, at the desk: the remote desktop indicator repeats what the scale on the hook shows, without anyone walking into the bay.

What a Bluetooth crane scale is not

It is not permission to stand closer. The fall-zone rule does not change because the display moved; it only becomes easier to keep, because nobody now has a job that requires breaking it.

It is not a substitute for the stamped reading in trade. If the scale is used to buy or sell — scrap by the tonne, castings by weight — the Legal Metrology Act, 2009 requires it to be verified and stamped before use, and the state enforcement rules name the crane scale among instruments verified at the premises, because it cannot be carried to an office. The verified display is the legal weight; the phone and the desk indicator repeat it. What the stamp means in practice is explained in what is government stamping.

It is not more accurate because it is wireless. The accuracy is the load cell’s. For a generic class III instrument under OIML R 76 — not a figure for any particular HSCo model — a 5 t scale with a 2 kg division would be allowed ±2 kg up to 1,000 kg and ±4 kg beyond on verification, and twice that in service. Bluetooth carries that number faithfully. It does not improve it.

And it is not long-range telemetry. Ten metres reaches the rigger and the desk beside the bay; a weight that must travel to the ERP across the plant wants a Wi-Fi scale or a cabled indicator — see the IoT connected weighing scales page.

What changes on Monday morning

For the rigger. He hooks the load, steps back to the painted line and reads the phone. Zero and tare come from the remote. He has no reason to walk under the load again.

For the clerk. The weight reaches the desk indicator or the app record exactly as the scale saw it. Nobody shouts a number across the bay; nobody copies it from a slip. A 2019 study in the Journal of the American Medical Informatics Association compared 6,930 instrument readings typed by staff against the same readings sent by the instrument itself: 3.7 % of the typed ones were wrong, and the authors’ advice was to interface the instrument wherever feasible. A 2012 PLoS One study of 21,887 fields found hand-written numbers the worst case, at roughly 7 errors per 1,000. A weight copied onto a challan is exactly that kind of number.

For the supervisor. Every lift can carry a time and a scale identity in the app, so Friday’s “who weighed what” argument takes a minute instead of an afternoon.

For the safety officer. One control moves from the administrative tier to the engineering tier — the change auditors ask for and rarely get.

How to start: one crane, thirty days

  1. Pick the one crane where the rigger most often walks under the load to read the weight.
  2. Size the scale by the heaviest load on that hook — 3 t, 5 t, 10 t, 20 t or 50 t.
  3. Fit it. Install the app on the rigger’s phone; give the clerk the desk indicator if the weight goes onto paperwork.
  4. Paint the standing line at about 8 metres, where the reading is reliable and the fall zone is not.
  5. Count for thirty days: times anyone stepped under a load to read the scale; readings re-typed; disputes over a weight.
  6. Roll out to the next crane only when the count says so.

Hindustan Scale Company has made weighing scales in Mumbai since 1955 and builds the crane scale, the radio, the app and the desk indicator itself — one supplier answers for the whole chain.

Frequently asked questions

What is a Bluetooth crane scale?

A crane scale that hangs on the hook and weighs the load as any crane scale does, but also sends the reading by a short-range radio to a phone or tablet app and, optionally, a desk indicator. The rigger and the clerk read the weight from outside the fall zone instead of from the display on the hook body.

How far away can I read a Bluetooth crane scale?

About 10 metres, line of sight, on HSCo’s CRHBT range. Treat the figure as indicative: steel racks, the load itself and the crane structure shorten it, and radio rules cap transmit power at 100 mW for every maker. Test the link from the spot where the rigger will actually stand.

Can a Bluetooth crane scale be used for buying and selling in India?

Yes, once it is verified and stamped under the Legal Metrology Act, 2009, which state rules arrange at your premises because a crane scale cannot be carried to an office. The stamped display on the scale is the legal weight; the phone and desk indicator repeat that weight.

Do I still need the display on the scale itself?

Yes, and it stays. The jumbo display on the hook body is the verified reading and the fallback if a phone is flat or out of range. The wireless readout adds readers; it does not remove the original one.

Which capacity should I choose: 3 t, 5 t, 10 t, 20 t or 50 t?

Size the scale by the heaviest load that will actually hang on that hook, not by the crane’s rating. A 5 t scale suits coils, billets and fabrication sub-assemblies; a 50 t scale reading a 2 t load gives a coarse figure. Indicative prices before GST run from ₹17,500 for 3 t to ₹68,500 for 50 t.

Does the phone app replace the desk indicator?

Either can be the only reader. The app suits the rigger on the floor and stores each lift with a time; the desk indicator suits a clerk who needs the weight in front of her all day without a phone. Many bays run both from the same scale.

Next step

Tell us which crane the rigger walks under most, and we will propose a thirty-day Bluetooth crane scale pilot for it.

Hindustan Scale Company (HSCo) · Mumbai · est. 1955 · www.hindustanscale.com · hsc@hindustanscale.com

Sources

  1. Bureau of Indian Standards — IS 13367 (Part 1):1992 Safe use of cranes — Code of practice, Part 1: General, clause 13.3 (all persons stand clear of the load) and clause 17.1.1 (weight of the load to be known before lifting).
  2. US OSHA — 29 CFR 1926.1425 Keeping clear of the load (fall-zone rule) and 29 CFR 1910.179 Overhead and gantry cranes, (n)(3)(vi) (avoid carrying loads over people), (n)(1) and (b)(5) (rated load).
  3. The Factories Act, 1948 (India), section 29 — lifting machines: safe working load plainly marked and never exceeded; 12-monthly examination by a competent person; register.
  4. US Bureau of Labor Statistics — Fatal occupational injuries involving cranes, 2011–17 (CFOI fact sheet): 297 deaths; just over half struck by an object; 79 struck by an object falling from or put in motion by a crane.
  5. Heliyon 9(12) e23587 (2023) — “Identification and analysis of hoisting safety risk factors for IBS construction based on the AcciMap and case study”: 105 hoisting accidents in China, 38 struck by the hoisting load.
  6. UK Health and Safety Executive — Work-related fatal injuries in Great Britain, 2025/26: 126 workers killed; struck by moving object 21.
  7. Scientific Reports (2026) — “Improving workplace safety at EOT crane operating area through behavioral-based safety approach: a case study analysis” (Tamil Nadu factory).
  8. NIOSH / US CDC — Hierarchy of Controls (2024); CCOHS — Hazard and Risk: Hierarchy of Controls (2024).
  9. The Times of India — “2 workers die after steel beam lifted by tower crane falls on them from 6th floor at Navi Mumbai site; FIR” (21/08/2026). Single newsroom; attributed in the text.
  10. Marine Insight; The Times of India; Hindustan Times; Baird Maritime; Maritime Gateway — container-stack accident at a Nhava Sheva (JNPA) terminal, 07/07/2026 (a weather-toppled stack, not a crane lift).
  11. The Legal Metrology Act, 2009, section 24; Andhra Pradesh Legal Metrology (Enforcement) Rules, 2011, Rule 17(2) proviso and Schedule XI (also Chhattisgarh 2011, Bihar 2014) — crane scales verified at the premises.
  12. OIML R 76-1:2006 — Non-automatic weighing instruments, Tables 3 and 6, clauses 3.5.2, 4.2.3 and T.2.2.6 (secondary display).
  13. Bluetooth SIG — Understanding Bluetooth Range; ETSI EN 300 328 V2.2.2 (2019-07), clauses 4.3.1.2.3 and 4.3.2.2.3 (20 dBm e.i.r.p. limit).
  14. Paulsen A., Overgaard S., Lauritsen J. M. — PLoS One 7(4): e35087 (2012); Mays J. A., Mathias P. C. — Journal of the American Medical Informatics Association 26(3) (2019).
  15. Hindustan Scale Company — CRHBT5K Electronic Bluetooth Crane Scale product page and related models (September 2026); indicative prices before GST.