Launched just over a year ago, the CAT S61 is one of the most rugged smartphones currently available. Its MIL Spec 810G certification and IP69 rating mean it’s incredibly robust, as well as water and dust proof, making it ideal for use in hostile environments and tough working conditions. Neil Mead has been testing the S61 extensively over the last couple of months and has become quite fond of CAT’s latest flagship device.

We’ve seen a few rugged mobile phones appear on the market before, but they have generally been compromised in some areas, such as screen resolution, camera quality or even processor speed, making them difficult to use as an everyday device. Therefore, users requiring decent smartphone features and performance to use in difficult conditions have often resorted to rugged cases for regular smartphones. This may solve some problems, but can lead to others, so it’s not the perfect solution. Enter the latest S61 flagship smartphone built by Bullitt Group and carrying CAT branding, a device made to be used in difficult conditions that’s designed to last and which also has a few extra features that you won’t find on any other smartphone.

Built for professionals

The S61 is like a ’Swiss Army knife’ of smartphones as it not only has all the functions of a regular Android-powered mobile device, but it also houses a Flir thermal imaging camera, an air quality sensor and a laser measuring tool. These extra functions not only make the phone a gadget lover’s dream, but also a very useful tool for tradespeople, facilities managers, or anyone that might need to use these features for professional purposes. So although the S61 might be a little on the bulky side compared to a regular smartphone, it’s still a lot more convenient to carry around than four separate devices.

The S61 has been built for professional users who need these extra functions on a day-to-day basis. It’s not the most compact or lightest device, coming in at 162 x 77 x 13mm with a weight of 259g, it’s a substantial piece of kit. There are no concerns about its build quality though, as manufacturer, Bullitt Group has certainly made a product that should last. Part of the reason for this is the extra reinforcement needed to pass the two important certifications mentioned, MIL Spec 810G for strength and toughness and IP69 for water and dust proofing. There’s plenty of polycarbonate and rubber to absorb shock and protect the device from drops, and a metal frame to provide overall strength.

Design and function

As you’d expect from a modern smartphone, the front is dominated by a 5.2-inch IPS LCD capacitive touch screen which has a decent HD resolution of 1080 x 1920 (424 pixels per inch), with a widescreen 16:9 ratio, which actually makes it perfect for viewing video content. The screen is protected by both Gorilla Glass 5 and also a factory installed protector, both of which add to the phone’s ruggedness. In use the screen is just the right size to be able to navigate with one hand, yet large enough to enjoy watching video and other content.

Something a bit different to most smartphones are the three physical navigation buttons placed under the screen. These provide useful positive feedback that is only possible from ‘proper’ buttons and makes navigation easier, especially if using gloves. It is also possible to activate a ‘glove mode’ in the system settings which makes the screen respond even better when you have your hands covered. The phone doesn’t have a fingerprint sensor, so a passcode has to be used to unlock the device, which is fine, but can be a bit of a pain if you’re used to a phone that has either fingerprint or face ID unlocking. During my testing I ‘accidentally’ found a face ID unlock feature buried in the screen settings for the S61. It only uses the front-facing camera to recognise your face, so it’s not the most secure means of locking the phone, but it worked really well for me most of the time.

Above the screen is the earpiece speaker, 8MP front facing camera and a useful LED notification light. Above this is a significant CAT branded bulge which appears to house part of the Flir thermal imaging camera tech and certainly provides the phone with a unique look and feel. Moving to the edges of the device, there is the main speaker at the bottom, next to the centrally mounted USB type-C charger interface. On the left side there is a gold coloured user-programmable button that is located just below the covered dual sim tray, which can also be used to expand the phone’s memory capacity up to 256GB using a microSD card instead of a second sim if desired. On the top there is a covered 3.5mm headphone socket and on the right side you’ll find the main power button and volume adjustment keys. Just below these is another of the S61’s useful features, an indoor air quality monitor that measures humidity and ambient temperature, as well as the quality of the air. The results are displayed in an easily digestible traffic light format with red indicating dangerous levels of VOC (Volatile Organic Compounds).

The rear of the phone is covered in a non-slip rubber, which offers a really nice feel in the hand and plenty of grip. The back of the phone also houses the main 16MP camera as well as the Flir thermal imaging camera at the top, with another of the S61’s unique features, a laser-assisted distance measure tool, located nearer to the bottom. The S61 has a substantial 4500mAh battery fitted which does an excellent job of powering all these extra features and can be recharged rapidly thanks to the built-in quick charge technology.

The S61 isn’t meant to compete against other normal flagship phones, so it makes sense that it doesn’t run the latest chipset, but instead uses the slightly older, but more energy efficient, Snapdragon 660 CPU instead, matched with 4GB of RAM and 64GB on-board storage. The rest of the specification is fairly standard: 802.11ac Wi-Fi, Bluetooth 5.0, NFC, a 16-megapixel rear camera, 8-megapixel front-facer, fast charging capabilities (via Qualcomm’s Quick Charge 3.0 technology) and a small 18W power supply which does a good job of juicing up the phone pretty fast.

In use

There’s no doubt the S61 is a chunky and quite weighty device, but that just adds to its overall robust and indestructible feel in the hand. There’s no case required for this phone, it’s already very well protected and the rubberised back provides plenty of grip which means it can just be used straight out of the box, no matter where and how inhospitable the environment may be for regular mobiles.

The near stock Android operating system running on the decent mid-range Snapdragon 660 processor with plenty of RAM makes it feel quite fast and slick in use. Downloading, installing and then swapping between apps poses no problems for the S61 and I didn’t notice any lag or stuttering at all, everything runs smoothly and efficiently. Just like any other regular smartphone running the Android operating system, the user interface can be easily customised and it can run all the apps you might want to use which can be downloaded from the Google Play Store. I installed plenty of apps, including the usual social media favourites and also used it for a number of email accounts, including Gmail and my company’s Microsoft Exchange account and everything ran well without any syncing or connection issues.

YouTube videos play well and look crisp and clear on the HD LCD screen. Sound from the single bottom-firing speaker is also very clear and can be turned up quite loud without any noticeable distortion. Having a 3.5mm headphone socket is handy as well if you need to listen to something in a noisy industrial environment. As a phone it works as well as expected, with no reception problems and crystal clear calls. In fact callers reported that I sounded louder and clearer on the S61 than my usual iPhone device.

So the S61 gets all the basics right, but it’s the extra special features that really make it stand out. Having a Flir thermal imaging camera in your pocket and easily to hand at a moment’s notice is incredibly useful for a facilities manager. Add to that the always on air quality metre and the CAT S61 starts to look like an invaluable tool for the professional, not to mention the laser assisted measure, which again is right at your finger tips.

The verdict

With a sim free retail price of £799, the S61 isn’t a cheap device, but taking into account the hardware that’s crammed inside, it offers genuinely good value for money. A dedicated Flir thermal imaging camera, a standalone VOC meter and a laser-assisted distance measuring tool are likely to cost just as much, which means that essentially you’re getting a great quality and fully featured Android powered smartphone for free. This is likely to be a phone provided by an employer, so it would probably then become a second ‘work’ phone, but there’s absolutely no reason why it couldn’t serve as a primary device. We’ve shown it to a number of facilities managers and tradespeople who have all been extremely impressed by it.

The solid feel, smooth performance, great extra features and excellent battery life all add up to make the CAT S61 a fairly unique device and the current undisputed king of rugged smartphones. If you need a full-featured smartphone that will stand up to the rigours of every day life on site, or if you just want a tough device with excellent battery life, this is definitely the phone for you.

To find out more about the CAT S61 smartphone, please visit the dedicated CAT phone website at: www.catphones.com

CAT has also produced some ‘how to’ videos and posted on Youtube to help users get the best out from the S61’s measure and thermal imaging features which can be found at https://www.youtube.com/playlist?list=PLf43vPekY8UYBovF5p6tALi-hfuVAy-oM and https://www.youtube.com/playlist?list=PLf43vPekY8UYlSG780DhlQIpIgPSMNPKk

CAT S61 Specifications

  • CPU: Snapdragon 660
  • GPU: Adreno 508
  • RAM: 4GB
  • Storage: 64GB
  • Screen size: 5.2-inch
  • Resolution: 1920 x 1080
  • Weight: 259g
  • Dimensions: 162 x 77 x 13mm
  • Rear camera: 16MP
  • Front camera: 8MP
  • OS: Android 8.1
  • Battery: 4.5Ah