Home raising20 December 2000
New hoists and cranes have boosted productivity and safety for a US modular home manufacturer
When Eric and Paul John, the current owners of the Ritz-Craft Corporation in the USA, set out to build a new modular-home manufacturing plant, they had three goals in mind:
make it a state-of-the-art facility
improve safety and ergonomics.
By using 63 electric chain hoists and 19 cranes made from crane kits by Harrington Hoists, as well as making other strategic facility design decisions, Ritz-Craft checked off all three items on the agenda. As a result, Harrington helped the Mifflinburg, PA-based family-owned and operated business to meet the three main criteria at its fourth new factory which opened for production in February 2000.
Eric John explained: “When we conducted a review of our three factories in Pennsylvania as we prepared to build a new plant, we observed a number of places where we could improve our production lines.
“Using that knowledge, we believed we could design the new Jonesville Ritz-Craft plant to be more productive by keeping materials inside and increasing our employees’ access to them.” With the help of Harrigton distributor, Elkhart Industrial Fabricating, in Elkhart, Indiana, John designed a thoroughly modern facility with 175,000sq.ft. (16,100m2) of floor space. The new Ritz-Craft plant contains several large crane systems, hoist-operated material elevators and scaffolds, as well as 20,000sq.ft. (1,840m2) of mezzanine flooring.
The mezzanines serve as a second floor for storage and off-line fabrication. Together these features have already contributed to the plant’s quickly developed status as a state-of-the-art facility within the modular-home manufacturing industry. And there are great expectations for the future. Working in combination, these features are expected to raise Ritz-Craft productivity to an all-time high.
New lifting equipment
Most of the 63 hoists and 19 cranes have either one-, two- or three-ton capacities and are used for common applications. Among these basic activities are lifting, moving or placing the floors, exterior walls, interior partition walls, ceilings and roofs that are assembled to make a Ritz-Craft modular home.
Harrington’s Series 3 motorised end trucks with their externally adjustable brakes, side guide rollers for less friction, and standard rubber bumpers, gave Ritz-Craft the quality and features needed for the operation.
Harrington hoist and crane products are also used in other ingenious ways. The Jonesville plant, for example, employs a 200ft (61m) span, three-runway crane system built from Harrington components that allows the employees to “do just about anything,” according to John. “We can pick up shingles or entire bundles of sheeting off a mezzanine in the back of the plant, and then transport them out to the assembly line to cover the modular home unit,” he added. “The crane system, one of the most efficient I’ve ever seen, features Harrington end trucks and trolley hoists along with a spreader beam designed by the installer to pick up our roof assemblies. We employ it to make sure everything underneath is working and lining up correctly.” While most of the 63 electric hoists are somewhere within the crane systems, Ritz-Craft dedicated 24 hoists, each with a capacity of 2 ton, to a high-tech scaffolding system. John pointed out that the Jonesville plant features a moveable scaffold, 3ft wide by 80ft long (1m x 24m), at each of 12 stations. A 2 ton capacity hoist, placed on each end of the scaffold, allow the scaffold to be raised and lowered anywhere from 4ft to 22ft high (1.2m to 6.7m). Ritz-Craft employees keep supplies on the scaffold and workers have instant access to materials at each job elevation by positioning the scaffold using hoist controls.
This special arrangement is to help increase productivity when putting up siding, and working on the roof. Harrington’s single-fall 2 ton ER series hoists meet the duty cycle demands of the Ritz-Craft operation and provide the travel and lifting speeds needed as well as continuing operation in 15° side pull applications. Multiple hoist lifts, common in the modular-home industry, frequently result in side pulling and can ruin chain and chain guides when the hoist is not properly designed.
Four more electric 2 ton hoists are committed to two material elevators at the end of the production line. These elevators, 8ft wide by 40ft long (2.5m x 12m), and powered by a hoist at each end, start at the mezzanine level. They can be lowered all the way down to load dormer units which are then hauled up for placement on the modular home. These hoists are also used to carry appliances from loading docks to the units in progress.
Raising the roof on productivity
John remarked that the addition of the crane and hoist systems has yielded a significant increase in productivity, when compared to other Ritz-Craft facilities. “In Pennsylvania, we spend a lot more hours on the forklift. For instance, when doing the roofing work there, our employees use a forklift to bring in a skid of shingles, then hoist it up to the top of the roof. Then they go back and get another skid until the roof has been spread with shingles.
“In Jonesville, the crane system moves down and picks the skid off the mezzanine where employees have set up enough shingles to do all the houses for the day.” John adds: “The forklift there isn’t tied up lifting shingles every hour and a half.” In addition to making materials more accessible, the Harrington hoists also help to reduce maintenance time due to quick-disconnects on the pendant. “Seventy-five percent of the problems we’ve experienced with hoists is that our operators get the push-button control cord caught on something when setting walls or ceilings,” John reported. “Typically, when this happens, we have to shut down the hoist and wait for maintenance personnel to fix it.” But because the hoists have quick-disconnects, any Ritz-Craft employee can be lifted in a forklift bucket to unplug the broken unit and quickly replace it with a new one. “It now takes only five minutes, instead of 45 minutes, to finish the repair,” he said. “And that results in higher production.” Other productivity-enhancing features include higher lifting speeds, according to Elkhart Industrial, which specified the hoists and crane components. It was explained that most competitors’ 2 ton hoists are simply a 1 ton hoist with the chain doubled and a block placed at the bottom in an attempt to multiply the capacity. While this does increase capacity, it also turns a 16ft/min (5m/min) hoist into an 8ft/min (2.5m/min) hoist. Harrington’s single-fall 2 ton hoist provides 14ft/min (4m/min) lifting speed. In this business, productivity is very important and the lifting speed of the hoist has a direct effect on productivity.” According to Harrington Ritz-Craft has been more than satisfied with the productivity enhancements the hoists and crane components have introduced, and the company has added more Harrington hoists to lift and move a new form of dry wall. It comes in large panels, 8ft by 24ft, (2.5m x 8m) as opposed to more typical 4ft by 8ft (1.2m x 2.5m) sheets. Ritz-Craft also requested the installation of a Harrington motorised end truck for the powered material handling carts that are to be integrated into the new side-wall and ceiling jigs.
“Obviously we are really pleased with the Harrington products because they have given us a big productivity boost,” John says. “They have really helped Ritz-Craft become more efficient, which makes it easier and safer on the employees and pays off for us all in the long run.”