WoW Grimrail Depot Heroic Guides

Grimrail Depot is a 5-man dungeon in Gorgrond introduced with Warlords of Draenor.

If you¡¯ve ever wanted to enjoy the sights of Draenor by train, then this isn¡¯t the ride for you. If you want fast paced action on a moving train, then we¡¯ve got you covered. The Grimrail Depot is a level 100 dungeon and a vital hub in the Iron Horde war machine. Allowing for the transport of troops and materials produced in the Blackrock Foundry to the front lines of the war being waged across Draenor, the Depot¡¯s namesake is the Grimrail itself. This massive train can bear entire battalions of troops and artillery. Fitted with a massive railgun powerful enough to shatter the shield protecting Shattrath, the train is about to depart. Do you have your boarding pass It¡¯s going to be a heck of a ride.

Players encounter three explosive bosses who are packing some serious gadgets and fire power. This train isn¡¯t stopping for anything or anyone.

Grimrail Depot is a Level 100 dungeon in Warlords of Draenor available in Normal, Heroic, Mythic, and Challenge Mode difficulties. It is located in Gorgrond, and takes place primarily on a moving train and the depot that services it. This guide will outline strategies and important role-based responsibilities for each of the three bosses in Grimrail Depot, as well as some tips on particularly threatening trash mobs.

The entrance is close to Blackrock Foundry, Gorgrond (click for map).


Players who have built the Lunarfall Inn / Frostwall Tavern in their Garrison have access to several quests that can be completed in Grimrail Depot, some of which reward vanity items.
  • Cold Steel can be completed on any difficulty and rewards a cosmetic Bloody Bandanna.
  • Cleaving Time can only be completed on Heroic difficulty, and rewards Gamon's Braid.
In 6.2.3, completing this dungeon for the 1st time a week on Mythic difficulty rewards 300. The first random heroic of the day also awards 100.

Mythic Dungeon bosses now also have a chance to drop a new Heirloom Trinket that will scale up to level 110: Judgment of the Naaru, Orb of Voidsight, Infallible Tracking Charm, Purified Shard of the Third Moon, Gronntooth War Horn. Note the Demon-themed procs to fit in with Legion.

Players who complete Challenge Master: Grimrail Depot are awarded the title %s the Grimrail Suplexer.

You can complete the achievements This Is Why We Can't Have Nice Things and No Ticket towards Glory of the Draenor Hero which awards Frostplains Battleboar.

When Sign of the Emissary is active during Draenor Dungeon Event, Heroic and Mythic trash mobs grant 20 Council of Exarchs/Frostwolf Orcs reputation, and bosses grant 400 reputation. Defeating 4 Mythic dungeons for Emissary of War awards a Iron Fleet Treasure Chest.

Players working on the legendary ring questline must complete Core of Iron to get Core of Iron.


Loot from Grimrail Depot Normal is ilvl 615. Loot from Grimrail Depot Heroic is lvl 630. Mythic loot can range between ilvl 685 and ilvl 725, in increments of +5 ilvls. The higher the ilvl, the smaller chance there is to obtain it.

Normal-mode dungeon gear has the chance to have a tertiary stat, and Heroic-mode dungeon gear has the chance to have a tertiary stat, Extra Socket, and/or be Warforged for a +6 item level boost. Mythic Warforged gear is a +20 ilvl boost, not +6 like heroic.

Most dungeon loot can drop from bosses across several instances, and there are more potential items for one gear slot than in the past. Below we've listed the trinkets and weapons that are unique to Grimrail Depot as well as what other types of gear you can get from that boss. Click here to see the loot shared among bosses in other instances.
  • Nitrogg Thundertower: Scepter of Brutality, Thundertower's Targeting Reticle, chest, neck
  • Railmaster Rocketspark: Overseer's Final Word, ring, waist
  • Skylord Tovra: Arrowbreaker Greatshield, Thunderlord Flamestaff, Tovra's Lightning Repository, gloves, wrist, legs

Visit the Grimrail Depot and boss pages linked above to see complete loot tables, as well as basic Dungeon Journal information on all the fights.

Rocketspark and Borka

Notable Trash Mobs:

Grimrail Technician will periodically run to a nearby Iron Star Mk. III and begin Activatingit. If this cast is allowed to finish, the Iron Star Mk. III will deal heavy party-wide damage. This cast can be interrupted and stunned, and the Technicians can be crowd-controlled.

Technicians also cast 50,000 Volts on ranged DPS and healers, which deals heavy damage and chains between nearby players. Stay spread out to avoid chaining this. On Heroic and Challenge Mode difficulties, this also stuns the affected targets. 50,000 Volts cannot be conventionally interrupted, but players can stun or CC the Technician during the cast to prevent it.

Rocketspark and Borka Tips & Strategy:

The Railmaster Rocketspark andBorka the Brute encounter is fast-paced and requires a lot of awareness, especially from the tank.
  • Rocketspark will fly around the room, launching VX18-B Target Eliminator missiles at two random targets, while Borka stays grounded and periodically Slams the floor in front of him.
  • Rocketspark will occasionally fly up into the air and become untargetable, channeling X21-01A Missile Barrage; the tank must interrupt this by pointing Borka in Rocketspark's direction so that Borka's Mad Dash strikes Rocketspark and knocks him down.
  • Hold threat on Borka; Rocketspark cannot be tanked
  • Use minor defensive CDs for each Mad Dash
  • Aim Mad Dash at Rocketspark's current position to interrupt X21-01A Missile Barrage
  • If players defeat Rocketspark before Borka, use powerful defensive cooldowns to survive Borka's Unmanaged Aggression
Damage-Dealers' Responsibilities:
  • Focus damage onto Rocketspark whenever Rocketspark is attackable, so that the two enemies' health is depleted as evenly as possible
  • Avoid being in the path of Mad Dash
  • Move out of the VX18-B Target Eliminator
  • Use DPS cooldowns to help finish off the surviving boss after one boss has died

Move out of Target Eliminator
Healer's Responsibilities:
  • Slam and Missile Barrage create party-wide AoE damage
  • Avoid being in the path of Mad Dash
  • If the tank misses Rocketspark with Borka's Mad Dash ability, party damage will become quite high, due to the Locking On! mechanic. This will expire naturally, but may require a minor cooldown to keep the party alive
  • Move out of the Target Eliminator
  • Use your cooldowns during the final portion of the fight when only one boss is alive. Tank healing demands will be very high if Borka is the remaining boss, so use cooldowns such as Pain Suppression or Ironbark. Party healing demands will be very high if Rocketspark is the remaining boss, so use cooldowns such as Healing Tide Totem or Aura Mastery.
Heroic and Challenge Mode difficulties:
Borka's Slam will now also interrupt spell casting, locking the player out of the affected spell school for a brief period. Casters and healers should target or focus Borka to watch for his Slam cast and avoid using cast-time spells as it finishes.

Nitrogg Thundertower

Lava Wreath

Notable Trash Mobs:

Grom'kar Gunner:
  • Grom'kar Gunner have a powerful flamethrower attack, Shrapnel Blast, that stacks rapidly on any players standing in the area of effect and deals heavy damage.
  • The Gunners are rooted in place while they channel the attack, so tanks should keep them faced away from the party and move behind them when they start the channel to avoid taking excessive damage.
Grom'kar Cinderseer:
  • Grom'kar Cinderseer afflict a random ranged DPS/healer with Lava Wreath, which silences the player for up to 12 seconds and deals fire damage to players within 10 yards.
  • The silence effect is reapplied every time Lava Wreath deals damage, but is removed instantly if there are no other players within range.
  • Ranged players should ideally spread out so that the Lava Wreath deals no damage and its silence effect fades almost instantly, but if this is not feasible due to the heavily restricted space in these train cars, the affected player should run away from the rest of the party immediately.

Nitrogg Thundertower Tips & Strategy:

Use Homing Shell to injure Assault Cannon
Players originally engage Nitrogg Thundertower in a cramped section of a train car, and he uses only a few abilities for this brief period - Blackrock Mortar and Blackrock Grenade. Avoid stacking up inside the train car to limit damage taken.

Once Nitrogg reaches 60%, he will flee to man his Assault Cannon. At this time, the sides of the train car will open, allowing players to bypass the cargo blocking their path and engage the Assault Cannon, as well as a number of reinforcements that Nitrogg summons to aid him. Once the Cannon has been destroyed, players may finish the task of killing Nitrogg directly.

Tank's Responsibilities:
  • Many, many adds to pick up! Most important are Grom'kar Boomer and Grom'kar Grenadier, while Iron Infantry are weaker and less important to gather
  • Break line-of-sight with the Assault Cannon if targeted by Suppressive Fire, by ducking behind a pillar
Damage-Dealers' Responsibilities:
  • Use throughput CDs to shorten the adds/Assault Cannon phase
  • Prioritise Grom'kar Boomer, then Grom'kar Grenadier, then the Iron Infantry. You can place DoTs or otherwise attack the Assault Cannon between waves of adds
  • Quickly loot the Grom'kar Boomer's body to gain a Blackrock Mortar Shells
  • Once you are carrying a Mortar Shell, click on a Blackrock Turret and use the Homing Shell ability on the Assault Cannon to damage it. Players must hit the Cannon with 3 Mortar Shells to destroy it
  • Loot a Grom'kar Grenadier's body to gain a Blackrock Grenades, granting you an Extra Action Button. Pressing the button allows you to target an area and throw a Blackrock Grenade at it, dealing very heavy damage to all enemies in the area. The Grenades have 3 charges and should be used when there are Grom'kar Boomer adds active
  • Break line-of-sight with the Assault Cannon if targeted by Suppressive Fire, by ducking behind a pillar
  • Avoid stacking on other players to limit damage intake and avoid being interrupted by Blackrock Grenade from the Grom'kar Grenadier

Line-of-sight Suppressive Fire behind a pillar
Healer's Responsibilities:
  • This portion of the fight has spiky damage on the tank as well as party members. Use your raid CDs when the party is in danger
  • Being struck by a Grom'kar Grenadier's Blackrock Grenade will knock you into the air and briefly lock you out of a spell school if you were casting at the time. Avoid stacking on other players to limit your chances of being targeted
  • Break line-of-sight with the Assault Cannon if targeted by Suppressive Fire, by ducking behind a pillar
Once the Assault Cannon is destroyed, the fight is very simple. Adds stop spawning, so players can focus on defeating Nitrogg.

Heroic and Challenge Mode difficulties:

Avoid standing in Slag Blast
Nitrogg's Assault Cannon gains a new ability, Slag Blast, which covers a section of the train car in highly dangerous flames.
  • There are three "segments" of the train car that can be targeted by this, and players should move to an unaffected segment.
  • This is especially important for the player who is avoiding Suppressive Fire by line-of-sighting the Cannon behind a pillar; the combined damage from Suppressive Fire and Slag Blast is fatal.
In addition, another type of add spawns, the Grom'kar Gunner.
  • Gunners must be tanked facing away from the party as they have a powerful cone ability, Shrapnel Blast, identical to the trash in the earlier train cars.
  • When Gunners are killed, players can loot Blackrock Shrapnel, unlocking the Shrapnel Cannon ability from Blackrock Turrets.
  • The player carrying the Shrapnel can board the Turret and use this ability to quickly kill adds. Tanks should be sure to tank adds close to the Turrets.

Skylord Tovra

Notable Trash Mobs:

Grimrail Scout:
  • Grimrail Scout cast Arcane Blitz, which spawns small pools of Arcane energy that inflict very heavy damage to players standing within them.
  • The spell has a long cast time, but cannot be interrupted, although stuns will work. Players can preemptively move to avoid taking damage; players who stand in the Blitz are likely to die.
Grom'kar Far Seer:
  • Grom'kar Far Seer buff themselves with Storm Shield, which absorbs damage dealt to them, and attacks against the Far Seers while the Shield is active will trigger a chain lightning that deals moderate damage.
  • The spell cast can be interrupted, although it is a very quick cast, but it cannot be dispelled; it will fade after 10 seconds or when the damage-absorption shield is broken through.
  • Healers must be prepared to handle moderate party-wide damage.

Skylord Tovra Tips & Strategy:

Skylord Tovra is a very straightforward fight. Players must move away from Freezing Snares, avoid standing in the path of Spinning Spears, and move out of the Diffused Energy pools created when Rakun flies overhead and casts Thunderous Breath.

Each time Thunderous Breath is used, a larger portion of the platform will be blanketed in Diffused Energy; this serves as a soft enrage for the fight.

Note that if you are affected by Freezing Snare's root effect, it cannot be dispelled, but it can be countered by snare-breaking effects such as Blessing of Freedom, (Spell #137562), Stampeding Roar, and Windwalk Totem.

Diffused Energy (left); Freezing Snare (middle)
Tank's Responsibilities:
  • Keep Tovra pointed away from other players in case Spinning Spear targets you
  • Move Tovra away from nearby Freezing Snares and Diffused Energy pools
Damage-Dealers' Responsibilities:
  • Move away from other players if targeted by Spinning Spear
  • Move away from nearby Freezing Snares and Diffused Energy pools
  • Melee DPS should try to move with the tank to avoid being stranded by intervening Diffused Energy pools
Healer's Responsibilities:
  • Most of the damage in this fight is tank damage
  • The party will take moderate AoE damage every time Rakun casts Thunderous Breath
  • Players who stand in Diffused Energy will take heavy damage
  • Move away from other players if targeted by Spinning Spear
  • Move away from nearby Freezing Snares and Diffused Energy pools
Heroic and Challenge Mode difficulty:

Hunter's Mark and Explosive Spear
Tovra gains an additional ability, Hunter's Mark, which targets a random player and launches an Explosive Spear at the player's location.

Targeted players should move during the 6-second Hunter's Mark debuff to avoid taking damage, and as much as possible, players should be spread out to avoid unnecessary movement.