Talk across the site without taking a glove off
A crane operator, a pump crew, the material gate and the site office on one channel, with the phone staying in a pocket and the screen staying off. Nothing to buy, nothing to issue, nothing to charge in a cradle at the end of the day.
Three things happen at once, and someone has to tell everybody
The pour has already started. What matters is how long it takes to get one sentence to four people who are not standing together.
PTT Talkie
Phone calls
A group chat
Built around the parts of a site that break other tools
A whole sentence, gloves on, phone away
A one-second press of the volume-up key starts talking with the screen off. A short tap still only changes the volume, so a phone in a jacket pocket does not start transmitting every time something knocks against it. Nobody has to remove a glove, and nobody has to look at a screen to be heard.
One channel, or one per trade
The whole site can share a six-digit channel, or you can split by trade and floor and give each group its own number. A channel has an owner and admins with mute and remove, so one person can keep a busy channel usable during a pour.
Basements, lift shafts and steel frames
Coverage on a site is patchy by nature. The app notices a dead connection and re-establishes the channel by itself rather than asking anyone to restart it, and voice that arrived while someone was underground is replayed in order when they come back into coverage.
An honest word about noise
No app can make a breaker or a concrete pump quiet. The audio is speech-optimised at a low bitrate and fills in very short dropouts so a sentence stays intelligible, and in sustained noise a headset makes far more difference than any setting. Where a site genuinely has no coverage at all, a handheld radio still wins.
The situations sites ask about most
| Crane and ground | Both on one channel instead of hand signals at distance |
|---|---|
| Gloves and dust | One-second hold of the volume key; a short tap only adjusts volume |
| Lift shafts and basements | The link drops and the app reconnects on its own |
| Older phones on site | Android 7.0 and above, roughly 6.8 MB, no Google Play services |
| A noisy pour | Speech-optimised audio that keeps short dropouts intelligible |
| A full shift on one charge | Background listening keeps the channel open, with a guide to battery settings |
One number per group, or one for the site
Most sites start with everyone on a single channel and split it once the traffic justifies it.
Ground crew and crane
Slinging, lifting and setting down, with the operator hearing the same words as the banksman.
Concrete and structure
Pump, formwork and finishing crews keeping one sequence instead of three separate plans.
Materials and deliveries
The gate calling the store so a delivery does not wait for someone to walk over.
Services and fit-out
Electrical, plumbing and ductwork coordinating in the same rooms without crossing paths.
Supervision and client
Site management and the visiting client hearing the same updates as the crews.
Night and weekend work
A smaller crew on the same channel, with the site office reachable from home.
Four things that matter on a working site
All of these are standard features rather than add-ons.
A one-second hold of volume-up transmits; a short tap changes the volume as usual, so a pocketed phone does not open the channel by accident.
Each member shows as online, listening or offline. A call sign that goes unanswered is visible as such instead of being repeated blind.
The app detects a dead link and reconnects by itself, and a server-side update does not drop the crew out of the channel mid-shift.
Android 7.0 and above, a single APK of about 6.8 MB, and no dependency on Google Play services.
What to sort out on day one
Two minutes of setup saves a week of confusion.
Questions from site managers
The short answers, including where a handheld radio is still the better tool.
Can people use it with gloves on?
Yes. A one-second hold of the volume-up key transmits with the screen off, so nothing has to be tapped on a touchscreen. A short tap only changes the volume.
What happens in a basement or a lift shaft?
The connection drops and the app re-establishes the channel by itself once coverage returns. Voice that arrived while the person was out of range is replayed in order, so a message is not lost while someone is underground.
Do we need to buy handsets for everyone?
No. The app runs on the Android phones the crew already carries. Many sites keep a couple of handheld radios for areas with no coverage at all and use the app for the rest of the site.
Can the crane operator talk to the ground?
Yes, if both are on the same channel. The operator hears the same voice as everyone else on the channel, with no hand signals or shout across a gap.
Will it work in a noisy area?
The audio is tuned for speech and bridges very short dropouts, but nothing makes a breaker quiet. For sustained noise a headset makes the biggest difference, and that is a hardware choice rather than a setting in the app.
The phones on site are old. Will it install?
It needs Android 7.0 or newer and about 6.8 MB, and it does not require Google Play services, so phones without the Play store still work.
How do we keep different trades apart?
Give each group its own six-digit channel. Most sites start with one channel for everyone and split by trade or by floor once the traffic makes it worthwhile.
Put one site on one channel this week
Download the APK, choose a six-digit number, and try it on a real shift before deciding anything else.