FM Global DS 8-34: Shuttle ASRS Fire Protection in Detail

A shuttle ASRS is a horizontal-loading automated store in which shuttle robots running on the rack levels move small containers and trays. FM Global DS 8-34 (July 2017, interim revision April 2026) covers these systems in Sections 2.2.2 to 2.2.4. One point to note: in DS 8-34 the term "vertically enclosed" does not describe shuttle racking but packaged lift or carousel units (Section 2.4, Appendix A). For the general rules, see the DS 8-34 overview.

Shuttle ASRS Rack Configuration

• Containers or trays rest on slatted or mesh shelving without vertical alignment guides, so the rack structure does not divert water away from the flue spaces. This is the difference from mini-load (3.1.1, Appendix A).
• Rack uprights are about 75 mm wide and 2.4 to 3.0 m apart along the aisle; tier heights are roughly 0.3 to 0.6 m (Appendix A).
• A small container is typically about 400 × 600 × 375 mm, or slightly wider in footprint but no more than 450 mm high (Appendix A).
• Anchor the racks against overturning and a domino effect, allowing for water-filled in-rack piping and fire protection water collected by the containers (2.2.1.3).

Ceiling-Only Protection

• Closed-top, noncombustible, solid-walled containers used throughout: protection is designed for the surrounding occupancy hazard (2.2.2.1).
• Closed-top combustible containers or trays: ceiling-only protection is possible with vertically aligned flue spaces (2.2.1.4), aisles at least 1.1 m wide (1.2 m where the ceiling exceeds 9.1 m or uncartoned expanded plastics are stored) and an option in Tables 2.2.3.1.2(a) to 2.2.3.1.2(j) (2.2.3.1.1). Table 2.2.3.1.2 selects the table by commodity, material handling (directly on the rails or on trays) and wet or dry system. For example, Table 2.2.3.1.2(a) (wet, Class 1 to 3) gives options up to a 16.8 m ceiling, with 1.8 to 2.4 m aisles required at the highest levels.
• Open-top combustible containers: ceiling-only protection is possible only where storage does not exceed 3.0 m (2.2.4.1.1; Table 2.2.4.1.2(a) for wet systems, Table 2.2.4.1.2(b) for dry).

In-Rack Sprinkler Design

• In-rack sprinklers are FM Approved, quick-response, 160°F (70°C) storage sprinklers (2.2.1.6.2.2).
• Closed-top combustible containers or trays: select the horizontal arrangement from Table 2.2.3.2.1 by rack depth, flue spaces, commodity, ceiling height and aisle width (Figures 2.2.3.2.1(a) to (e); maximum on-line horizontal spacing 1.5 m). For wet in-rack systems, Table 2.2.3.2.2.1(a) gives vertical distances from 3.0 m to 12.2 m depending on the arrangement, commodity and flow, for example 12.2 m for Class 3 in the Figure 2.2.3.2.1(a) or (b) arrangement with K22.4 (K320) at 455 L/min. The lowest-flow option, K5.6 (K80) at 115 L/min, requires hydraulic balancing with the ceiling system (2.2.3.2). Dry in-rack systems use Tables 2.2.3.2.2.1(c) and (d).
• Open-top cardboard or unexpanded plastic containers: select the horizontal arrangement from Table 2.2.4.2.1 (Figures 2.2.4.2.1(a) to (e); in-rack sprinklers at every other transverse flue space, with on-line spacing not exceeding 1.5 m). Table 2.2.4.2.2.1(a) allows a maximum vertical distance of 3.0 m (minimum K11.2 (K160), 380 L/min in most arrangements) or, for some wet arrangements, 4.6 m (K14.0 (K200) or K22.4 (K320)) (2.2.4.2).
• Where tiers are less than 225 mm apart vertically, add 75 L/min to the in-rack flow; never use a design pressure below 0.5 bar (footnotes to Tables 2.2.3.2.2.1 and 2.2.4.2.2.1, 2.2.3.2.2.3, 2.2.4.2.2.3).
• The ceiling design is selected from Tables 2.2.3.2.3.1 and 2.2.3.2.3.3 (closed-top) or Tables 2.2.4.2.3.1 and 2.2.4.2.3.2 (open-top) using the distance between the top in-rack level and the ceiling; where no option exists, install a noncombustible false ceiling able to resist an uplift of 14.4 kg/m² or an extra level of in-rack sprinklers above the storage (2.2.3.2.3, 2.2.4.2.3).

Detection, Robot Shutdown and Final Extinguishment

• An FM Approved ceiling-level fire detection system over the storage area per DS 5-48; under obstructed ceilings the detectors follow the maximum ceiling sprinkler spacing (2.2.1.7.1, 2.2.1.7.2).
• On activation, an alarm to a constantly attended location and automatic shutdown of the robots (2.2.1.7.3).
• Small hose connection stations near the aisle access points, each of the two most remote delivering at least 190 L/min (2.2.1.8).
• Robot electrical systems, lithium-ion batteries tested to IEC 62619, maintenance of charging contacts and annual infrared scanning (2.1.6); DS 7-110 for control systems (2.1.7).
• A pre-incident plan with the fire service covering access to the fire, dismantling of racking where needed, and which containers will be removed and where they will go (2.1.5).

Quick Checklist

• Rack confirmed as shuttle type (slatted shelving) per Appendix A
• Container material and open or closed top identified
• Transverse flue spaces and aisle widths measured
• Ceiling-only conditions (2.2.3.1.1 or 2.2.4.1.1) checked
• Horizontal in-rack arrangement from Table 2.2.3.2.1 or 2.2.4.2.1; vertical distance and flow from Table 2.2.3.2.2.1 or 2.2.4.2.2.1
• Ceiling design from Tables 2.2.3.2.3.1, 2.2.3.2.3.3 or 2.2.4.2.3.1–2.2.4.2.3.2, matched to the in-rack system
• Detection shuts down the robots; hose stations and pre-incident plan in place

Frequently Asked Questions

Is ceiling-only protection enough for a shuttle ASRS?

It can be. For closed-top combustible containers or trays, ceiling-only protection is possible with vertically aligned flue spaces, aisles at least 1.1 m wide (1.2 m where the ceiling exceeds 9.1 m or uncartoned expanded plastics are stored) and a suitable option in Tables 2.2.3.1.2(a) to 2.2.3.1.2(j) (DS 8-34 2.2.3.1.1). With open-top combustible containers it is possible only where storage does not exceed 3.0 m (2.2.4.1.1).

Does a shuttle ASRS need in-rack sprinklers at every level?

No. DS 8-34 defines in-rack levels by distance in metres, not by tier count. For closed-top combustible containers on a wet system, Table 2.2.3.2.2.1(a) gives vertical distances between 3.0 m and 12.2 m; for open-top containers Table 2.2.4.2.2.1(a) allows a maximum of 3.0 m, or 4.6 m in some wet arrangements.

What do the shuttle robots do in a fire?

DS 8-34 requires the fire detection system in a horizontal-loading ASRS to send an alarm to a constantly attended location and automatically shut down the robots on activation (2.2.1.7.3). It does not define moving the robots to a particular safe position or a fire service bypass; such details belong in the pre-incident plan prepared with the fire service (2.1.5).

What fire detection is used in a shuttle ASRS?

DS 8-34 calls for an FM Approved ceiling-level fire detection system over the storage area installed per DS 5-48, without mandating a particular brand or technology (2.2.1.7.1). It is not needed where closed-top, noncombustible, solid-walled containers are used throughout the array (2.2.1.7.4).

How does a mini-load ASRS differ from a shuttle ASRS?

The difference is the rack support. In a mini-load rack the containers sit on angle irons that divert sprinkler discharge to the rack face, whereas in a shuttle rack they rest on slatted or mesh shelving and water can reach the flue spaces (DS 8-34 3.1.1, Appendix A). That is why the two types use separate ceiling and in-rack tables.

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