I don't know if anyone else picked up on this, but...check out the hose slung into a 90 degree bend.  A disharge hose is meant to aim down, right?  In theory, if the hose had a small 'hiccup', it would blow the discharge downward.  What would a small 'hiccup' do when discharged out of this hose that's bent in this sling contraption?

The reducing hose is debatable as to it's safety - but C'mon!!!???  are you serious???  a hose slung into a 90 degree bend???

I highlighted, in blue,  the verbage that irritated me the most.

Figure 2 below shows other methods of keeping the concrete from falling out of the boom by the force of gravity. These alternate methods do not pose a hazard to the workers, and may work better than the double “S” system to prevent loss of entrained air.

Oh,Raymond my dear.

I did spot that but was only trying to be politically correct in my response ( the other acpa topic)

I will say I believe in the acpa principles fundimentally,they are like a 50 cal machine gun,have to set the head space and timing for proper operation.

I truly believe this bulletin should be trashed,I agree with the statements about the double 90s but there solutions to the problems are ridiculous neither is a safe alternative,why not just show steel reducers these have been around for years and are the solution to the air entainment issue,not hose whip we are gonna have to work a little harder on solving this problem, but I do know reduction hoses and bending that hose in a 90 is not the answer,usually the ACPA is rite on ,but they missed this one by a mile

I am doing some study about this very important issue before I weigh in on this post.

I hope that everyone posts a response to this.

YOU ARE THE GUYS that have to do this every day..

What is your opinion? Your opinion matters!!!

The first illistration (left) is just not a viable option on any type production pours.I have approached an issue only a couple of times that was close,single sided forms to help control load speed.These are only extreme conditions that even scared the burrito lady across street.

The second illistration is more viable of sorts.This would more fall in line with company policy and what they are willing to spend and job requirements.As I recall 2 recent concerns

1) air entrainment

2) ICF

The first is what contractor ordered (4-7% the norm) this is a delivered spec not in place.At DIA we learned delivered at 10% usually gave good tests at point of placement.Another consideration is how tester got his sample (full streem or splattering) and getting them out of wall pipes is a joke.

ICF is a different animal,I believe the crews need more training and education.If they built them right and used the proper adhesives (in correct spots) they wouldn't have an issue with us blowing there forms out.We did a 3 story ICF at Buckly AFB and those guys did it right,3 1/2" tip hose baby.

Beyond that perhaps we have become more complciant with reducers and how to abuse them.Somehow I see self reducing/antiwhip hoses becoming the norm as they appear to be the lessor of the evils.I for one would at least carry a 5-4 reducer and 4" tip as a back up.We that live long enough will see many more safety related changes in this industry.I personally hated cruise contol and mufflers,ahhh the sound of those 8" sewer pipes and a jake.

Good or bad that's my take

I don't know if I would be willing to add that sort of "possible" hazards to myself,This stuff is dangerous enough, in my mind, not to add, what seems to me as senseless risk. We are put in ridiculous situations every day as it is due to some of the questionable intelligence of some contractors out there. Would it not be as easy and simple for them to properly build their forms to meet the needs of the situation? This is my ongoing gripe for management of the pump company's to stop hitting nudy bars in their Tahoes and talk to and educate the customer on the equiopment they have on their sites.

'

So we've just turned our concrete boom pumps into guns!!!

Probably not the smartest solution.

My response under original Todd post

ACPA safety bulletin

well personally the illustration looks like a joke, as soon as concrete would reach the past the point of the strap it would be so heavy it would weigh down on the hose causing it to pinch,as for the reducing hoses, any reducing should be kept in the steel(5-4 reducers ect.)and thats my take on the subject