If a non car enthusiastic plant designer was to click on his remote he could end up on a channel that, just then, happens to be showing the sequencing of a series of lights. These particular lights will signal the time for “popping the clutch of dragster”. His main attention would most likely be on the torque the “huge” engine generates onto the “huge back tires”; he has designed many an installations where large electric motors accelerate towards full speed and transfer that power to a set of mill rolls, if only for a short duration. He would watch the back tires deform under the torque until the torque would be replaced by speed. A few seconds later the parachutes open and the dragster coasts to a (near) stop. The front tires are small (he notices) as the initial torque attempts to raise the front and once the parachutes open, he knows, very little force is again applied to the front. Soon after, the lights are shown sequencing again but, his thought may again be on the application of torque and he may dismiss the fact that the lights and the track are the same, but it is not the same machine this time. When he designed a plant, the motors, reducers, mill, the rolls were repeatedly the same but the billet/round going through it was not. The cycling was frequent, the rolling times were short and, as with the drag races, it kept on going and going (till in this case it was time to change the channel).
The next channel, oddly enough, again showed racing, but, this time it was at Daytona. The cars were going around and around at high speed, occasionally braking fast only to accelerate again, and again, around and around they would go. Being a designer, he immediately recognized that this time the tires appeared to be equal, in front and back. From his training he knew, the back tires, as before, applied torque. But, due to the repeated cycling of acceleration/de-acceleration, the front tires were, in this case subject to high forces during braking (and cornering, so the front tires had to be of good size as well). As the track banked and curved, he suspected the suspension, steering, etc. had to be designed for the specific conditions. Since the speeds appeared to be high, he suspected, whoever was responsible for the design of the car, knew “his stuff” and was able to produce a car that performed well at racing.
Had he stayed long enough on this channel, he would have seen something that didn’t appear in the first of the two channels (for obvious reasons). That would have been a “pit stop”. At Daytona the race lasts long enough to necessitate, maybe switching of the tires, adding fuel, making minor adjustments, removing bent metal (due to minor mishaps), etc. etc.. He would also have noticed that the pit stop was so short, for all that had to be done, that one may wonder if the driver even bothered to put the car on neutral but only kept the clutch pressed down till the pit crew gave the signal to get back in the race. He would perhaps have also realized that not only did the designer do “his thing” for the race but, if the pit stops took too long, there would be “no money” at the end of the race. Thus the designer has to design, not just for racing (or producing a product) but making sure the availability for race (or production) is maximized or there is “no money” at the end.
In rolling mills, the buildings are usually longer than they are wide. The width sometimes is not wide enough to accommodate the drive motors which end up being behind the adjacent wall (also to keep them away from the mill environment). The space on the opposite side (from the motors) may not be free of obstructions either. The overhead crane(s) occasionally is just one but usually maybe two or more. Usually they bridge along the length of the building and trolley across the width. The main transport/train doors may end up at one or both ends of the building, depending on many factors. Having truck access doors on the sides may be less common. If one looks at where the maintenance people are located, one may find them somewhere in the basement or where they themselves have found enough space to build a work table and place tool box.
During the repair shift, and depending on the complexity of equipment, there may be several “big jobs” happening at the same time. As lot of the equipment (if not most) is of such size that only the overhead crane can lift/position. As there has been considerable development and improvement with the hydraulic/mobile hoists, if the floor space allows and there is available access one may increase the options by using such hoists. But, if the old/new has to be transported, due to lack of floor space, there can be long delays when one overhead crane is “tied up” and in the way. There are plants where the over head cranes bridge across the building, either at same or different elevation than the more traditional longitudinally travelling cranes. These across bridging cranes would need to be strategically located after actually giving thought to maximizing the long term operating time of the plant. Depending on how the designer provides and designs for the maintenance (pit stop) may determine if there is “money at the end”.
Not all equipment is inside of an enclosed building. Refineries, Coke Oven by-product plants and many other similar installations are mostly exposed to the elements. In such plants the process generates heat and as long as the process is functioning as designed, there is not problem from the elements. A problem can become very serious if there is a partial breakdown and the temperature of the now stopped flow falls below freezing or where the equipment is no longer designed and able to handle at the fallen temperature. As with the vehicles (race cars), as long as the engine is running, one can have the engine filled with just circulating water (no antifreeze although antifreeze solution provided other benefits such as higher boiling point than by just with water). But, if the engine stops working in sub zero weather, one better get the engine working, out of the environment, or drain the water from the engine. In a complex plant situation, none of those solutions are nearly as easy as they would be for finding a solution with a stopped engine. The crew may get the section that “froze” first thawed out but by that time another section has now “frozen”. Around and around this can go on, lasting, if not for hours maybe stretching even into days. If the designer had not provided for such occasions, the corrective measures are now in the hands of the maintenance. But, they are affected by the problems at hand, maintenance budget restrictions, defined manpower levels, etc.. To finally have the problem eliminated for long term solution, it may take months if not even into a year or more. There are ways to reduce, if not even to eliminate this kind of problem, only if they had been applied at the design stages.
Not all of the above may be for how the designer would deal with it. Some could be for how the capital investment moneys are decided on by the customer or as defined by the scope of the project. Some companies may place all the available moneys on that which produces the product and have the production start to pay for the maintenance as the plant is in production. But, if no thought has initially been placed on addressing the ultimately inevitable maintenance, it “may be too late” to take any reasonable and corrective measures; in which case it ends as a problem for most of the life of the operation or with a much higher than the cost of providing in part or totally at the start of the project.
Companies such as Wabi Iron & Steel Corp. have the capabilities to re-engineer obsolete industrial plant replacement components, either as a casting, or a fabrication, or as a combination of both.