This is the second part of an article that ran in the January-February issue of MM&D. The first part discussed how questions of column spacing, ceiling clearance heights and flooring should be approached. Click here to read the first installment.
All merchandise received and shipped from the DC will flow through the dock doors, so it is impossible to put too much effort into the planning and design of this feature. Dock spacing must be sufficient for trailer movement into and out of the docks and also must coordinate with the interior equipment layout. This becomes especially critical with high-capacity conveyors and sortation systems. Door openings must not restrict access for loading and unloading—but at the same time, must allow for seal and shelter installation. Dock plates need to be wide enough and long enough for the range of trailer sizes to be handled, and provide sufficient capacity for the equipment and loads to be moved in and out of trailers.
Building contractors and designers typically place the rainwater leaders, sprinkler pipes, electrical conduits and ductwork on the same side of each building column throughout the facility, but this isn’t a necessity, and adhering to arbitrary positioning may impair the function of the DC. Facility capacity will be reduced if the building services interfere with racking installations. The rain water leaders, sprinkler pipes, electrical conduits and ductwork should be located so they do not interfere with any materials handling equipment installation. If a lift truck hits a sprinkler pipe it can set off the fire alarm, shut down all the automated equipment, and cause the evacuation of the facility. Additionally, after the water flow has been stopped there is the water damage and clean-up of wet product, water-soaked equipment and a large puddle or pond on the building floor.
A solution often used as protection for all rain water leaders in the shipping and receiving area is to install a U-shaped steel plate, which is about one metre (three feet) high and painted safety yellow to make it more visible.
Mobile power equipment and traffic flow
One key building design feature that shouldn’t be neglected is the height of doorways between building sections: doorways must be higher than lift truck masts. Depending of the type of operation, doorways may need to be over six-metres-high (20ft). If there is a lot of mobile equipment traffic between building sections, then installing two doorways with traffic lights to indicate one way traffic direction for each doorway improves product flow and makes for a safer environment.
Barriers, guarding, banger bars, railings and bollards can be installed to protect all mobile equipment door openings, dock doors, man-door vestibules, computer infrastructure cabinets and workstations to prevent staff injuries, product damage and equipment damage.
Interior walls can be protected using six inch by six inch by half-inch angle iron (or larger) lagged to the floor about 30cm (12in) away from the wall and painted safety yellow for visibility. These items are often overlooked. Additional planning with a small increase in cost will support long-time use, while protecting your investment.
A common obstacle found in large buildings is structural wind bracing. Working very closely with the building designer, carefully select these locations. “K” bracing that starts about four metres (12ft) above the finished floor is often used instead of “X” bracing to reduce the impact on operations.
Building Automation System (BAS)
Taking an integrated approach to all parts of the design is critical to a simple, energy-efficient design. One building automation system (BAS) to control all the ceiling fans, exhaust fans, heating systems and lighting is recommended. Having many complex and expensive systems all talking to each other may not be required. Instead, use an integrated approach which clearly defines the relationships and interdependencies of each building system.
The early involvement of the design team into all phases of a project can improve the final result and a few of the lessons we have learned are:
- The heating and ventilating roof top units should be facing downwind to avoid snow accumulation and wind driven pollen.
- Design the roof structural steel to allow duct work to pass through.
- “Right size” the heating systems for an efficient operation.
- The maintenance staff will appreciate it if you build full-width access stairways with a walk-out door onto the roof so it’s easier to carry filters, replacement parts and tools onto the roof.
- Install power outlets on the roof near any large heating or ventilating units for power tools and test equipment.
- Select fluorescent lights instead of metal halide lights. The initial cost is higher, but it usually takes less than one year to recoup that cost in electrical savings, and you will continue to cut costs over the years with a lower electric bill.
- In addition, you can turn lights off during the day if skylights provide enough light, and use motion sensors to turn light fixtures on and off.
- Continue to consider LED lights, since manufacturers are developing LEDs with longer bulb lifetimes and with better energy efficiencies.
From experience, we found that small ceiling fans work, but very large ceiling fans work much better. Air moved by a very large ceiling a fan—specifically a destratification type—provides a more comfortable environment for staff. An important note to remember is that the operation of a very large ceiling fan must be connected to the fire alarm system so it shuts down when the alarm sounds, allowing the ceiling-level sprinklers to do their job.
On the subject of a centralized uninterruptible power supply (UPS) system versus an electrical distribution system throughout the facility versus a decentralized system offering an equivalent quality, we are undecided. If there is a lot of change in the facility over time the decentralized system is preferred.
A painted floor path in a facility ensures the smooth and safe flow of people and mobile equipment. If you want walkway and area floor painting to last, all lines need to be shot blasted and painted with epoxy paint.
To make the environment even safer, consider using different line colours to indicate purpose or use. Yellow, for example, can be used for walkways, white could be for area limits or mobile equipment aisles, and red could be used for egress paths to building exits. Also remember the most effective and visible lines are four- to six-inches wide.
Basing your signage on the American National Standards Institute (ANSI) sign standards ensures your signs convey clear concise messages all your staff and visitors can comprehend. The ANSI standard consists of four elements: colour, signal word, image and text. This standard process for signage design communicates warning awareness, processes, hazards, and procedures employees or others may encounter while in a DC, and ensures that individuals are informed of their health and safety risks, and the protection/control measures they may use in order to conduct their daily jobs safely and effectively.
It’s also a good idea to provide in-plant offices since it improves the group work environment, enables better communication, and increases productivity. Locate operations managers within the physical operation and closer to their teams. Include the support facilities in your design—coat rooms, print rooms, janitor closets, kitchenettes, training rooms, lunch rooms, electrical panels and electrical rooms.
To maximize the utilization of the building space, you can construct two or more floor levels, but keep in mind elevators may be needed to be provide barrier-free access to these offices or mezzanine areas.
Having the right complement of knowledge, experience and skill collaborating on the facility design will ensure a better chance at delivering a useful product to your client. In our experience, the inclusion of a highly creative and experienced architectural firm is a valuable addition to the early design team. You may not have the luxury of commissioning an architectural firm to spearhead the design. However, in bringing this type of experience to the table early, you will be exposed to different perspectives on distribution facility design. A reputable firm is focused on introducing flexible design options based on industry best practices, as opposed to cost control principles. A careful balance of creativity, cost control and future, flexible operational efficiencies is best
Edward Stevens is the pseudonym of a Canadian retail supply chain professional with over 30 years of experience in the industry.