Steel versus wood is a discussion that has been going on for a long time in the elevator world. Which material is better for an elevator cab?
For those of you not familiar with elevator cabs, they are the part of the elevator you ride in. The cab is attached to a sling and platform that is either pushed by hydraulic jacks or pulled by steel cable ropes. That is a bit of of an over simplification, but what it comes down to is the cab is the box that you ride in. As you will find with most things, opinion is usually the deciding factor led by who is doing the arguing or who benefits most. More on that later, but first, lets go over some important facts about cabs.
Whether wood or steel, cabs are built to be durable, reliable and safe, and every elevator cab produced today are all of those. Also, current elevator cars strictly follow the elevator code for the jurisdiction they are installed in. They are inspected and must pass the code to be placed into service. That is one way we know they are safe. So, when you are discussing elevator cabs, none of those points are important in arguing either way. Elevator cars are highly functional and safe. Therefore, it comes down to a few other factors that are still important, but not life and death. I have divided this analysis into three categories and most of the deciding factors between steel and wood fall into those. The first is the cost, the second is the quality of the ride (sound), and last but not least, the ease of installation.
Cost – When it comes to cost, steel is simply more expensive. In general terms, a steel elevator cab is twice as expensive as a wood core cab. We know this because we will place any type of cab into elevators here at Phoenix Modular Elevator, wood core and steel. We produce wood core cabs in the factory, but frequently buy steel cabs for customers when specs are specific and steel is required. But, the cost of purchase is just the beginning. There are lots of hidden costs that are not usually understood or discussed when it comes to steel versus wood core.
The most important factor that drives up the costs for elevators (besides gold inlaid, mahogany hand rails) is the weight. The heavier the load lifted, the more expensive to install and operate. For cars of similar measurements and the same capacity, the weight for a steel cab over a wood core can be up to 15% higher. That means increased power requirements. It can mean bigger jacks, motors and valves, different motors or sheaves requirements, as well as ropes. All of this can cost more money not just in the short term but in the long run. Check mark to wood core!
Quality of Ride or Sound – Hello, hellllo, hellllllllo. Sorry; just thinking of standing in a steel elevator cab makes me imagine I’m in a Ricola commercial. I just couldn’t resist. A metal cab is louder. It is not a myth that you can sound like you are in a tin can, because you are in a tin can. There are ways to reduce the noise transfer, but then cost becomes an issue again. Also, when there is noise in an elevator, that usually means there is vibration and that can cause connections to loosen, creating even more noise and, of course, the need for repairs. In the old days, there were some drawbacks regarding wood core and moisture absorption, but with technology, that has largely been alleviated, so you will never get the creeks and moans with wood core that you get in a steel cab.
There is something very solid feeling about a wood core cab. One of our installers, when they first toured our factory, went in a fully constructed cab and jumped up and down and loved how solid the wood core cab felt. Also, wood core is just as flexible when it comes to design. If you can imagine it, a wood core cab can be it. Check mark number two to wood core!
Ease of Installation – Finally, a win for steel. One of the primary reasons for the movement away from wood core is the ease of installation of a steel cab. They come in pieces that are an easy fit through hoistway doors to the hoistway where most cabs are assembled. This can also help when modernizing the cab. They come apart pretty easy (hence the rattling) and can be replaced quickly. The wood core cabs likewise come in pieces, albeit larger than the steel pieces, and are put together with simple draw bolts. They can be taken apart easily as well. Of course, all of this is a moot point for our elevators as we build the cab outside of the hoistway and then insert and wire it prior to shipping. This means that the cab, whether steel or wood core, get built faster and easier.
So this is the real nub of the whole discussion. When you say that steel is better, who is it better for? Is is better for the end user? The answer is no. Wood core and steel are really the same. Steel is a bit louder and can rattle more by transmitting more noise, but the safety and functionality are equal in all other respects. Is steel better for the building owner? Nope. They cost more money upfront and over time and are subject to more long-term maintenance. Is steel better for the big elevator companies? Finally, the reason they are sold. Elevator companies find them easier to install (because they are not built like our modular models) and so they have become the standard despite the shortcomings.
To sum things up, either option is fine and we install both. Just keep an open mind to cost savings in the short and long term. That should be the ultimate determining factor.