Tau Codex Review: Fortifications: Tidewall Gunrig

When you need the most inaccurate weapons platform possible, and you need it slowly drifting across the field at the pace of a lazy infantryman, you call… the Tidewall Gunrig. Click to read on, or check out the Tactics Corner for more reviews and strategies.


The Tidewall Gunrig is part of the series of fortifications that were originally released as combined kits; these “networks” no longer have rules unique to them, though the pieces can still be taken together if you wish. The Gunrig featured in several of these formations of fortifications and was arguably one of the more useful parts of things, though this is perhaps no longer true. However, as (in theory) a defensive emplacement with a powerful weapon larger than can be mounted on almost any mobile vehicle and with good protection for its crew, the Gunrig on the surface level at least matches up fairly well with what a fortified position is supposed to be- though its game presence perhaps does not hold up quite so well to that.

Like its other cousin pieces, the Tidewall Gunrig has a statline that is about on par with your typical transport vehicle in most places, although for a fortification it is actually pretty weak defensively. Toughness seven is decent, if not amazing, and ten wounds is likewise a reasonable but not impressive number. 4+ armor is on the weak side, though, and ballistic skill 5+ is straight awful on what is supposed to be a shooting platform. A capacity of ten models is enough to generally hold what you need, although you will bump up against the limit if you’re trying to cram multiple characters and a large squad into the Gunrig at the same time. At 120pts, the Gunrig is definitely not cheap, although neither is it breaking the bank with its inclusion.

Special Rules and Wargear

Most of the Gunrig’s special rules are common to other fortifications in general and the Tidewall line in particular- like other forts you are free to shoot at units locked in combat with it (and shoot with it while a unit is locked in combat as well), and anything attacking it in melee hits automatically. It can move up to 6″ per turn if you have a Tau infantry unit embarked on it, and that unit is free to shoot out of the vehicle while embarked, although they must abide by all the normal restrictions when doing so. If destroyed, the Gunrig can explode for d3 mortal wounds to nearby units.

The Gunrig’s only unique rule is its Automated Weapons, which forces it to target the nearest enemy unit unless you have something embarked- as this will almost never be what you want to shoot at, you very much want to have something manning the Gunrig at all times, because its guns actually have a pretty good statline. The Supremacy Railgun is essentially two of the Hammerhead’s Railgun strapped together, although it unfortunately loses access to the submunition firing mode (much to its detriment)- two shots with S10 AP-4 and d6 damage (plus d3 more mortal wounds on a 6+) is nothing to sneeze at, especially with board-wide range. However, as a Heavy weapon the Supremacy Railgun is all but unusable when on the move, and even when firing normally is pretty unimpressive without buffs due to the extremely low native ballistic skill of the platform.


The Tidewall Gunrig isn’t good- we should probably put that right out front here. It’s expensive enough that you are having to invest some serious resources into making it work, but not actually all that effective either as a shooting platform or as a way to protect the unit inside. So don’t expect to see it climbing to the top tables anytime soon, because it’s got a lot of problems.

The biggest issue is its low ballistic skill, which is a problem shared by all fortifications with guns on them; BS5+ is an absolute joke, and even with two shots it means that as often as not your big ol’ gun platform will do absolutely nothing when shooting at the enemy. This is further exacerbated by the many, many factions out there with ways to give penalties to hit, not the least of which being Eldar; when your guns are hitting on 6s or even missing automatically, it’s very bad times. And if you’re not taking good advantage of the Gunrig’s weapons, it just ends up being an inferior version of the other fortifications, so making sure that you can try and get some use out of it is pretty important.

Fortunately, however, Tau have a fairly reasonable solution (or at least partial solution) to this issue: Markerlights. As you generally want to be hiding your Markerlights as best you can anyways, the Gunrig represents a pretty decent way to protect them while also buffing the effectiveness of your Gunrigs. A full squad of Pathfinders can fit inside a Gunrig and should typically be able to slap down those five Markerlight counters you want on a target that you’re focusing on, and if you bring a slightly understrength unit you can came a few characters (like Firesight Marksmen, for example) in there as well- a nice way to lower your drop count while protecting some of your most important units. With full Markerlight buffs active, a Gunrig is… well, it’s still a bit lackluster in some senses, but it’s much more dangerous than it would otherwise be. Hitting on 4s and rerolling 1s brings it to an acceptable, if not impressive, level of accuracy and it can give vehicles some pause in exposing themselves to fire. It can even negate the penalty for moving and firing, though it is worth remembering that the Pathfinders inside the Gunrig will suffer this penalty when attempting to build up your Markerlights, so I wouldn’t rely on that to do so.

We should pause and talk about the Supremacy Railgun itself for a moment here. As noted earlier, it has a very strong profile that is mostly limited by the platform it is carried on- but even ignoring that consideration, there are some significant limitations to keep in mind when using it. First off, with its small total number of shots there is a very high variance when using it; many turns of the game, you simply will score no damage at all even when using all your possible buffs and rerolls. The random damage on it makes this even worse, as sometimes even when you do score a hit and get past their defenses you’ll simply do 1-2 damage to a target, which is not what you want out of a weapon like that. On the other hand, the top-end variance is also quite high- it has the potential to do as much as eighteen damage to a single model in a single turn, with perfect rolls. The ability to push mortal wounds through on 6s shouldn’t be underestimated, although neither should it be relied on. Lastly, we should note that most vehicles that are successful in the current meta are ones with invulnerable saves, and often very strong invulnerable saves- this makes the high AP value on the weapon a lot less useful and limits its effectiveness against the only target you can realistically hurt with it. (You don’t want to be firing the Railgun at squads of infantry, although unfortunately against some armies you’ll have no choice but to do so.)

One other concern you should have when fielding the Gunrig is that it will always eat one of the detachments from your army; this can be obnoxious in any army, as it takes away some of your options, but in a Tau army it’s especially problematic because of the limit on Commanders. As Commanders are one of the most efficient shooting units you have access to, losing 1/3 (or more) of your access to them is a big hit and not exactly a great way to start an army, especially when you’re doing so for a unit that is not particularly exciting on its own. However, if you’ve committed yourself to doing so, make sure you make good use of that detachment- if you’re not taking two or even three fortifications in it, you may want to reconsider your plan.

One thing a lot of people miss about the various Tau fortifications is that they have the {Sept} keyword on their datasheet, meaning that unless you severely screw things up they will benefit from the Sept tenets out of the Tau codex. And unlike most of the other forts, they can actually make pretty decent use of this ability- Sa’cea sept is an obvious choice for the improvement to your accuracy with the Gunrig and is arguably the best choice, but don’t underestimate Da’yth sept in this case, either; the Gunrig generally wants to stay stationary anyways to avoid hit penalties and the sept bonus helps counteract the fort’s weak armor save. And you aren’t limited by the sept choices of the rest of your army, either- the Tidewall pieces can carry units of any sept, regardless of what affiliation you give them, so feel free to pick whichever one you think you’ll get the most use out of.


The Gunrig’s obvious weakness is any kind of hit penalties, which many armies have access to in a variety of ways. From subfaction traits to unit abilities to stratagems and psychic powers, there are tons of means out there to penalize the enemy’s hit rolls, and all of them will work quite effectively on a Gunrig as well as the Markerlights hiding inside of it. Invulnerable saves, especially those that are 4+ or better, will also drastically limit the usefulness of the Supremacy Railgun, so that is another big step in defending against it.

You also shouldn’t be too hard-pressed to blow it up the old-fashioned way, either; with only 4+ armor and ten wounds, the Gunrig will go down pretty easily to any kind of dedicated anti-tank fire. And if your list isn’t bringing at least that handful of Lascannons, Missile Launchers, Bright Lances, or whatever other equivalent your race has… well, you probably have a bad army to start with. Purely-melee armies may struggle to deal with it a bit, but such armies also probably bring so many bodies that the Gunrig is all but irrelevant to start with, so that’s something of a wash overall.

Final Thoughts

The Tidewall pieces in general are all pretty cool-looking terrain features, with the Gunrig in particular being especially so with its big, neat tower with a dual railgun mounted on it. However, as units on the tabletop they are pretty lackluster and don’t impress much, even for the more casual players out there; they could most certainly do with a bit of a price break come Chapter Approved, although this is probably expecting a bit much for a unit that many people forget even exists. Still, stranger things have happened, so we may yet see the day that Tidewalls make their appearance on the tabletop, much to the surprise and dismay of the Tau’s enemies.

As always remember that you can get your wargaming supplies at great discounts every day from the Frontline Gaming store, whether you’re looking to start a new army or expand an existing one.


About abusepuppy

AbusePuppy is the one who has been ruining 40K for everyone this whole time. He is also searching for the six-fingered man and is one of the three people who know the secret recipe for coke (not the soda, the illegal drug.)

17 Responses to “Tau Codex Review: Fortifications: Tidewall Gunrig”

  1. Charlie A. November 28, 2018 6:24 am #

    Even if the T’au fortifications were outstanding (which you’ve well-stated that they are not), they would have to truly be amazing to warrant giving up that detachment slot. As it stands, Fortification detachments seem to just be too punishing. I’d like to see other ways I could take fortifications, maybe in a Battalion for example.

    • abusepuppy November 28, 2018 8:20 am #

      I think that the loss of a detachment, while trivial, is something you can accept in the right circumstances and provided you’re actually gaining enough from whatever you are taking instead. But the Gunrig (and its cousins) are most certainly not that.

      • Charlie A. November 28, 2018 10:27 am #

        For T’au, the loss of the detachment is not trivial. Maybe for some other armies.

        • abusepuppy November 28, 2018 11:11 am #

          😛 That should’ve been “while not trivial.” It’s definitely a hit, but it’s not an unsustainable one.

  2. happy_inquisitor November 28, 2018 7:40 am #

    The rules for this are genuinely terrible; it feels bad to play it even in narrative games when your opponent brings one of the many armies with army-wide penalties to hit. Against eldar it is simply a handicap – you have given your opponent a head-start in points/power-level for nothing in return. Even if it got a dramatic points drop it would then just be a smaller handicap.

    I can find a use for almost anything in the codex but really this one was unfun even when playing Stronghold Assault. Mine does not even come out for armies on parade anymore, up close the detail on the model is crude compared to “proper” GW models. Hopefully nobody is still spending their money on this thing.

    • abusepuppy November 28, 2018 11:13 am #

      I think it’s better than the Tidewall Shieldline, at least, but yeah, it’s bad. The combination of inflexible (it only can shoot at multiwound targets effectively), inaccurate, fragile, and vulnerable to counter-strategies is just really, really punishing. The Tidewall pieces need to be something like half their current prices to be anything close to useable.

      • happy_inquisitor November 29, 2018 11:56 am #

        I found the cheaper useless waste of space to be fractionally less awful than the more expensive useless waste of space purely because it was cheaper but if your experience has been different that’s cool too.

        They are both useless and a waste of space in any list. I think we are agreed on that.

  3. Tim November 28, 2018 7:55 am #

    What order are you doing these in? ETA on a Y’vahra review? 🙂

    • abusepuppy November 28, 2018 8:22 am #

      Roughly from beginning to end of codex, although that is not 100% precise. (Astute readers will note that the Crisis review is not in yet, because I am holding off on that for reasons.)

      The Y’varha will probably be one of the first units on my list once I get to the Forge World section of things, since it’s a topic of contention for Tau players. So you have 2-4 more weeks of “standard” units to endure and then likely the Y’varha will get its day, along with the other FW choices in due time.

      • Dakkath November 28, 2018 12:51 pm #

        Fingers crossed that chap-app actually fixes crisis suits this time around.

        • abusepuppy November 28, 2018 5:34 pm #

          It’s doable, although I’m hesitant to say they would be a competitive choice even with a significant price drop. But with some changes to weapon prices and/or the price of the chassis, they could certainly start seeing some use, most especially because of the presence of Orks.

          • Dakkath November 28, 2018 7:58 pm

            Appropriately costed weapons, chassis, and Farsight getting the ability to take them as troops again are what I’m hoping for.

          • abusepuppy November 28, 2018 10:57 pm

            Eh, Troops isn’t really necessary with the way detachments work these days. But some changes are definitely needed in a couple places to make them work.

          • Dakkath November 29, 2018 1:58 am

            Can’t speak for others, but I’d love to take a FE battalion of coldstar, fireblade, and 3×3 (or more) crisis and gain 5cp out of it.

          • abusepuppy November 29, 2018 7:47 am

            I mean, yes, more CP is better than less CP. But you don’t get armies that shift things into the troop slot anymore, that’s not how the game works- DA don’t get bikes or terminators as troops, Craftworlds don’t get Wraithguard as troops, BA don’t get ASM as troops, IG don’t get Veterans as troops, and Tau don’t get Crisis as troops. If you wanna take an all-Crisis army you can do it, you just have to accept the hit on CP. (Or include some Kroot in there to clear the landing zone for them.)

      • NinetyNineNo November 30, 2018 4:58 am #

        Waiting to see if CA has Crisis changes?

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