In order to survive the batterings, drops and splashes thrown at them each day, toughened phones generally need to be hefty, armour-plated beasts. The CAT B15 is no exception.
It's fat and chunky, but this heft is due to it being water, dust and shock-proof. It has a 4-inch screen and runs Android 4.1 Jelly Bean. That means you can play with apps and games from the Google Play store on your break from building houses, chopping down trees or blowing up asteroids.
It's set to be available in the next month or so -- when retailers have been confirmed -- for £300. Interestingly, it has two SIM card slots. That'll come in handy if you regularly travel to another country and want to keep a local SIM card inserted at all times.
Should I buy the CAT B15?
If you've been lusting after a top-of-the-range Android phone to show off at your mate's house then no, move along to the HTC One immediately. If however, you're a builder, lumberjack, or anyone whose day-to-day activities involve a lot of dirt, action and general burliness, it might be the phone for you.
It's water, shock and dust proof, but unlike some other tough phones on the market, it also packs a host of smart phone features. It has a 4-inch touchscreen, which together with its Android software, means you can properly take advantage of the hundreds of thousands of apps from the Google Play store.
If you need a tough device for work, but can't afford to buy a smart phone for apps and games when you're not building things, the CAT B15 is a good compromise. If you only want the toughest phone for work and don't need apps, the Sonim Land Rover S2 might be a better option. Similarly, if you want a great Android phone you can spill a drink on, Sony's Xperia Z will be the phone for you.
Design and build quality
It's immediately obvious that the B15 is designed for a rough and tumble lifestyle. At 15mm thick, it's a lot chunkier than most recent smart phones. Its size, together with the rubber surrounds, makes it look like you've got a regular smart phone shoved inside a big protective case.
Its design is exactly what you'd expect to see from a company that specialises in producing mining machines weighing tens of thousands of tonnes. The black rubberised edging is offset by aluminium sides. The screwheads are showing on the sides too, which is of course an intentional effort to make it look more burly.
It's far from pretty, so it's not going to win you any favours if you whip it out on the catwalk. Its aggressive style and exposed screwheads might just draw a smile on the building site though -- all truly tough chaps love exposed screwheads.
The hardened looks aren't just there for show though. The B15 is designed to put up with the tough life faced by any builder's tool. It's IP67 rated, meaning it's waterproof to one metre for up to 30 minutes. Unless you're building a swimming pool, you're unlikely to submerge it to that extent, but it at least means it can handle on-site rain and an accidental dip in the foreman's PG Tips.
Splish, splosh, splash. The Cat B15 can have a lovely time in the water without having to worry about damaging its innards.
The screen has been designed to operate when wet, too. You can't use it underwater, but it's fully functional when covered in flecks of water. Many touchscreens aren't able to properly track a a finger when wet, meaning using them in the rain is a no-go. The B15 should still be responsive regardless of what you spill on it -- although I wasn't able to test it with wet cement.
It's drop proof up to 1.8 metres too. I did numerous drop tests onto a solid floor and found it held up fairly well. The screen showed no signs of cracking and the rubberised edges weren't damaged. On a couple of occasions though, the back panel did pop out, along with the battery. If you dropped it inside, it's not a problem, but having it expose its delicate internals like that might be a problem when you're out and about.
Sony's new flagship, the Xperia Z, has the same waterproofing as the B15, so if you're just after a mobile that can survive a dunk in the bath, that might be the blower to go for. Its all-glass front and back however means that it's not going to put up with much abuse in a manual work environment.
On the edges you'll find a power button, volume buttons and dedicated camera shutter button, all of which are bright yellow, presumably to make them easier to see when covered in mud. The volume buttons are easy to press but the power button on top sits very flush with the rubber surround. It's slightly awkward to press with a finger, so expect it to be almost impossible when you have thick work gloves on.
There's a micro-USB port and 3.5mm headphone jack too. They've both been covered by rubber seals to keep them waterproof, which makes them a bit awkward to access in a hurry. The B15 comes with 4GB of built-in storage as standard, but you can expand it with a microSD card.
On the front of the B15 is a 4-inch touchscreen. The iPhone 5 has a 4-inch display but of course, without all the protective casing, it's a much more pocketable device. The B15's screen size does at least mean that it's not stretching out your palm quite as much as phones like the 5.5-inch Galaxy Note 2.
It has a 480x800-pixel resolution, which falls far short of the Full HD displays of the HTC One or Sony Xperia Z. It's perfectly acceptable for the majority of day-to-day tasks you're likely to need on a building job though. Icons are reasonably sharp and small text on web pages is handled well enough. It's at least good enough to read email instructions or urgent messages explaining that the house you've demolished should have been the one the next street over.
It doesn't do a great job of displaying colours though. Images and video look somewhat washed-out and colourful games like Angry Birds don't have the same vivid punch you get from other phones. Its black levels aren't up to much so contrast isn't good and there's a small amount of light leak around the bottom edges.
All in all, the screen is very disappointing. If this was a top-end smart phone designed for consuming high-definition media, it would be a huge problem. It's really not designed with photo and video in mind though so it's difficult to hold this against it too much. It's pretty bright, but did throw up a few reflections under our harsh office lights. If you work on sites in bright sunlight, this might be an issue.
Software and processor
The B15 runs on Android 4.1.2 Jelly Bean, which is almost the most recent version of Google's operating system. Most phone manufacturers tend to tweak the standard Android experience in order to slide in its own software and services. CAT doesn't seem to have done much here though.
The Android interface is the same as you'd find on any standard Android phone. You have multiple homescreens to swipe through and fill up with apps and widgets. Four apps of your choice will remain along the bottom for quick access and you can jump into a grid of apps for anything you don't want on your home screens. Navigation is performed courtesy of three touch-sensitive buttons below the screen -- settings, home and back.