Joe Gibbs, sales and marketing director of US hoist and chain manufacturer Acco, that was the most vehement. He felt that the Hoist article The European Invasion was just the latest in a long line of displays by this magazine of an anti-American bias. It was nonsense to suggest that American hoist technology was lagging behind or that not much was going on in the way of new product development, was Gibbs’ point.

I tried to explain that there was no conscious attempt to ‘take sides’ but that after visiting the Promat show in Detroit earlier in the year, I had simply been struck by the increasing strength of European manufacturers in the US market and sought to establish why this might be.

This is not the first time this magazine has had bricks thrown at it. We are regularly being accused of being pro-Konecranes, anti-Konecranes, pro-Morris, anti-Morris etc. My line is that as long as I upset everyone eventually I must be doing something right!

For the sake of balance, I tried to persuade Gibbs to write an article setting out why, in his view, that the Hoist article had got it so wrong. He saw little point, he said, and was too busy. That being the case, I decided to visit Acco in York, Pennsylvania and see for myself what the company was up to.

At Acco, engineering director Bob Reisinger, who has been with the company more than 40 years, explained that since 1994 nine new Wright-branded electric wire rope hoists had been introduced by the company, including cross-mounted versions.

For high volume lifting there are the Work-Rated New Century Series hoists, in four frame sizes (called 32, 33, 34 and 35) and capacities of 1 US ton to 25 US ton, and an H4 duty classification. These are offered as single speed, two speed or inverter controlled.

For lower volume lifting, classified as H3, are the lower-cost but not dissimilar Speedway New Century Series hoists. Coded the 31 series, the Speedway is rated for lifts up to 5 US ton and inverter control is again an option. This Speedway is very different from the hoist of the same name that Acco produced between 1946 and 1974, Reisinger says.

Reisinger admits that when design work began on theses hoists in the early 1990s, he was influenced by the features that the European hoists were already offering. What they came up with, it seems, is a product line that has all the traditional ruggedness of American engineering with all the features of European hoists.

Acco/Wright hoists still have a load brake, of course, but that, as far as Gibbs, is concerned, is a total irrelevance to the debate. The key difference, it seems, between this particular American product line and those offered by European manufacturers is size. Acco’s hoists are big, heavy things compared to similar capacity European ones. They look like they are designed for hard work, whereas with certain compact European hoists it does not appear possible how they can lift what they do.

Acco hoists are also designed to be easily maintained. For example, remove the cover and all the gears are clearly visible and accessible.

What it comes down to, therefore, is customer choice. You can have performance from whichever side of the Atlantic your hoist is produced. It remains the case that the US product – in general – is a hefty piece of work compared to the light and compact European products, which some American manufacturers regard as looking disposable. What has aided the ascendancy of the Europeans is an approach which has designed-out cost. Being optimised, they cost less to produce because they are engineered only to the extent that they need to be.

Gibbs says he feels much happier selling Acco’s solid and rugged hoists than the lightweight and compact units that European competitors are offering.


V. Ramasubban, an engineer with one of India’s biggest steel mills, offers an independent view from a developing country on the article in issue 15 of Hoist, The European Invasion

It has to be admitted that European manufacturers have taken hoist engineering to a distinctly higher plane. They have succeeded in replacing the open barrel winch crab with compact hoist units even up to 40t. This is obviously a result of understanding the end-user requirements thoroughly. The hoists made by companies like Demag, Kone, and Stahl look more like a work of art. American manufacturers will take quite some time to catch up since this involves a change in mindset. In fact, Americans have been taken by surprise by this hi-tech invasion. One cannot win competition by harping on about features like mechanical load brake, low hoist speed etc. As more European hoists flood the market, the users will see the advantage themselves and start clamouring for more.

Speed war

A crane operator has absolutely no idea as to the speeds at which he is controlling the various motions. Ask any operator. He will tell you to refer to catalogues or manuals. His perception of speed is dictated only by the degree of comfort the controls provide him during manoeuvring. He can only be judgmental and say that the existing speed could have been higher or lower. In short, he is operating a crane that is provided to him by others (manufacturers and factory owners/ managers). It is their duty to provide him with a safe and efficient machine.

Presently, let us discuss only floor-controlled cranes with the control pendant independently mounted on a separate track since most wire rope hoist block cranes will be in this category.

How do we maximise the comfort level of the operator or more precisely, what should be the optimum speeds?

The travel speed is limited by the walking speed of man, which is 35m/min average. In a factory, due to obstructions and visibility from floor level, a speed in the range of 20m/min to 30m/min will be sufficient. Lower speeds can be chosen based on factory configuration. With higher speeds, the operator cannot keep pace and he will be uncomfortable. As such, there should be no difference of opinion on travel speeds.

But the hoisting speeds have generated a debate mainly due to a perceived safety hazard during lowering. To resolve this, we have to look at the basics. What is an overhead crane? Simply put, it is a facility to shift things from one location to another. The lifting function is only a prerequisite to carry out this shifting.

As such, the operator psychology is also predisposed towards the shifting function. One can lift just about a metre above floor level, shift the load and at the destination achieve desired lift for placement. But this is practically not possible due to factory layout and safety considerations.

So the safety cycle is:

• hoist to safe height

• traverse/ travel

• lower carefully.

It is the last one that Americans have apparently focused upon. With open loop systems they thought it wise to keep speeds low, and safe lowering is achieved by inching in steps. There is nothing wrong with this. The problem is, however, that since hoisting will also be slow speed, the operator will be tempted to operate the travel simultaneously or before reaching a safe height.

Europeans thought more logically: give high hoist speed to cross the operator’s patience threshold (30 seconds approximately) and for safe lowering give either half speed through a pole-changing motor or separate micro-speed or slip-ring motor with stepless thyristor drive to achieve even one tenth speed. Couple this with over-hoisting and over-lowering safety devices, you have a very safe hoist.

So even if Americans are right in a way, if someone has developed a system that works and satisfies all requirements, why not go for it?

For small loads up to 10t, hoist speeds in the range of 8m/min to 12m/min are very common and for 40t could be 4m/min. I have personally heard complaints about 3m/min being very low even though that load lifted was in the region of 70t. (This was a cab-controlled hoist crane with a lift of 15m.)

One question: Are the American elevators as slow?

Amazing but true…

It is amazing that the load brake still continues to be provided. This is a fall-out from the Thomson gearing system. Readers may recollect the photograph of the 100 year old crane in the Metrowagonmash factory in Russia, published in issue 12 (Oct/Nov ’00, p7). CMAA #70 recommends a load brake as one of several alternatives for hot metal handling cranes only.

It also surprises me that US hoist specifications call for a greater number of starts per hour in the motor while at the same time low speed is the trend.

And it is surprising that rope guides are required for a hoist having a four falls arrangement with two falls coming off the drum with right hand and left hand grooves. (Is the wire rope particularly stiff?)

In favour…

It can be inferred from the on-going tussle that US manufacturers are trying to justify their position in a self–consolatory way. Their concepts are quite in order for a nascent industry, but crane manufacturing is more than 100 years old and with technology advancements in electronics they have to reconsider their conventional electro-mechanical technology.

True, it is difficult to discard systems that have previously been marketed as great safety features. As such, the specification makers have a major role to play. They have to be more assertive, emphatic, practical and if need be initiate change in legislation and come out of the ‘disclaimer’ mind-set.

All said and done, the traditional US position has one very strong unassailable point in its favour: the conviction about true vertical lift without rope guides. That is, two falls paid off centrally from the drum, and deep grooves, pitches and diameter appropriate for fleet angles. There is no truer lift arrangement than this.

Hence, if US hoist manufacturers adopt higher speed, improve control systems and drop the load brake they can really come back strongly.