Manual Trolley & Hoist - Side Guiding/Pulling 1

[kotridge]

Dear Gentlemen,

Appreciate if you can put some light in to my problem.

Client has agreed to install a manual push/pull trolley and manual hoist (0.5 ton) over series of tanks with mixers.
Due to compact layout, the operator will only able to guide the hoist (and trolley) from the side way access.
The height of the hoist is 8 meters, and from operator it's making 13 deg angle. The hoist will have to cover 36 meters of traveling length of beam bellow which are the series of tanks.

What kind of manual hoist shall I use?
One vendor commented that guiding from side (more than 4 deg angle) is not recommended and will cause excessive wears on hoist?

The hoist is supposed to be used in rare occasion around once per year.

Some advice please.

Kind Regards,

 

[MikeHalloran]

Chain hoists tolerate that sort of abuse better than cable or strap hoists.
Slightly better if the hoist is connected to the trolley by a hook or swivel rather than being bolted or integral.

The ergonomics are still terrible, with the operator having to reach over the tank to pull on the hoist's operating chain to lift the load, and to yank sideways on the operating chain (not recommended) or the load chain (more awkward) to move the load.


It may be possible to build a small bridge crane with a manual chain loop of its own to drive the bridge. The operating chain still presents a problem. ... but small electric hoists don't cost a lot more than small manual hoists, and they can be equipped with a pendant and festooning so that the pendant hangs over the side of the tanks, not the center.

Given the likelihood of occasional back injuries with a monorail, your insurance carrier might have some suggestions.




Mike Halloran
Pembroke Pines, FL, USA

 

[tygerdawg]

Seems like this may have turned into not so much a crane lift problem as an ergonomics problem. It might require you to tell the client "whoops, let's reconsider" and suggest a pneumatic or an electric hoist. A bit more work, certainly more cost, little opportunity for manual hoist wear issues or ease-of-use issues, ergo problem eliminated. I know one company where Employee Safety really is priority #1 and that policy makes sticky decisions like this easy.

TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering

http://www.bluetechnik.com

 

[kotridge]

Thank you guys for the advice.

However, our client considers:

- electric hoist & trolley w/ festoon to be too expensive for once per year operation, in addition maintenance for hoist/trolley motor need to be considered also.
- chain loop to drive the bridge, the span of trolley beam is very long (37 m) thus the loop chain will be hanging like festoon in most places and also it will generate loud noise during operation.

is there any other option?
Or am i stuck with this option?

 

[MintJulep]

How about adding a cable loop to move the trolley along the length? Add a drop chain at one end to drive the loop.

 

[MikeHalloran]

The chain loop only has to drive one axle, from which it can hang. I.e., the chain loop would travel with the bridge, and be no longer than the operating chain loop of a manual chain hoist. No festooning needed for that. It would make a little noise in operation.

I disagree with your customer about the cost/benefit ratio of an electric hoist. In fact, the infrequent operation will guarantee that nobody remembers how to move the manual hoist without getting hurt. ... so the customer will be paying a back surgeon every few years. Still, their choice.

Maintenance on the hoist motor is a non-issue. At 1/2 ton, you throw the whole hoist away and order another one from Grainger.

Instead of festooning the hoist cable over 37m, they could let it dangle from the end of the bridge, next to the pendant, and just plug it in to a series of sockets located next to the tanks. Of course the plugs will be yanked out if possible, so the customer needs to plan a defense or a maintenance activity to deal with that.



Mike Halloran
Pembroke Pines, FL, USA

 

[potteryshard]

If a monorail chain hoist has to be operated from off to the side, that would seem to also imply that the load has be connected, manipulated, and controlled from off to the side. I would tend to think that would present more risk and out-of-position tugging than just jerking on the chain.

I would therefore suggest that the device be a bridge crane so the load can be manuvered as needed. However, there is nothing that mandates that the bridge have a drive. It can be pulled along with the load or the lift chain.

I built a bridge crane in my garage which used a chain hoist; it could easily pick up my project car, spin it around, move from one end to the other, and so on. Yes; at times there was a substantial angle between the load chain and the lift chain. I never found the angle between chains to be a problem; the hoist never bound or jammed, and the small horizontal force vector created by the off-angle chain was easily controlled.

 

[chicopee]

Is the material inside the tanks and its related vapor corrossive?