Does anybody else's mind wander while operating their tractor, or is it just me? The last few times I've run the loader moving dirt for hours at a time, the old advice that you should never double dip the pile to get a full bucket has danced around. It's been posted here, and in odd places like the operators manual for the loader. Yeah, I actually read the manual. :laughing: Anyway, is that advice sound??
let's do the math. Here's the set up. Assume ;
1) the bucket when fully filled holds 1 cu yard.
2) time to scoop the bucket into the spoils is 10 seconds
3) time to back up, readjust the bucket and hit the pile a second time is also 10 seconds
4) time to raise the arms and dump the bucket is 10 seconds
5) the bucket when filled a second time goes from 3/4 yard to 1 yard.
6) travel time from the spoils to a dump truck is 5 seconds
7) travel from the dump truck to the spoils is 5 seconds
So... how much dirt can you move in an hour of dedicated focused work?
One cycle of fill, transport, dump and return is;
10 seconds fill time + 5 seconds transport + 10 seconds dump + 5 seconds return = 30 seconds.
120 of these cycles can be done in an hour. Each resulting in 1 yard of dirt moved or 120 yards total moved per hour.
How much is moved in an hour if a second scoop is needed?
One cycle to fill, top off, transport, dump and return is;
10 s fill time + 10 s top off + 5 s transport + 10 s dump + 5 s return = 40 seconds
There are 3600 seconds in an hour, so 3600/40 = 90 trips can be made moving a total of 90 yards of dirt per hour.
Pretty obvious that 120 is more than 90! So the old advice is right.
But is that the whole story? What if your bucket is only filled to 75% and YOU DON'T TOP OFF??
You still get the same 120 cycles per hour, but each bucket only holds 3/4yard. 3/4of 120 = 90 yards of dirt. So, there is no net gain in dirt moved. Still seems like the old advice is sound!
But is it right for us small guys that are not dumping into a dump truck parked close to the spoils pile? Hmmmm.... If we adjust the assumptions a bit we can find out!
let's do the math. Here's the modified set up. Assume ;
1) the bucket when fully filled holds 1 cu yard.
2) time to scoop the bucket into the spoils is 10 seconds
3) time to back up, readjust the bucket and hit the pile a second time is also 10 seconds
4) time to raise the arms and dump the bucket is 10 seconds
5) the bucket when filled a second time goes from 3/4 yard to 1 yard.
6) travel time from the spoils to the dump site is 30 seconds
7) travel from the dump site to the spoils is 30 seconds
One cycle of fill, transport, dump and return is;
10 seconds fill time + 30 seconds transport + 10 seconds dump + 30 seconds return = 80 seconds.
3600 seconds per hour / 80 seconds results in 45 of these cycles done in an hour. Each resulting in 1 yard of dirt moved or 45 yards total moved per hour.
How much is moved in an hour if a top off scoop is needed?
One cycle to fill, top off, transport, dump and return is;
10 s fill time + 10 s top off + 30 s transport + 10 s dump + 30 s return = 90 seconds
3600 / 90 = 40 cycles per hour or 40 yards moved.
Here's the important calculation! How many yards are moved if you DON'T TOP OFF?
You get the same 45 cycles per hour, but each one only yields 3/4 yard for 33.75 yards total moved per hour.
Perfect fill = 45 yards
2[SUP]nd[/SUP] scoop fill = 40 yards
Imperfect fill = 33.75 yards
Aha! As suspected, the advice we have all heard is certainly valid → when the transport time is short. But, if you are moving dirt with the tractor bucket even a modest distance, it pays to ensure the bucket is full.
Ok, this might be useless information -- but it was bugging me, so I had to post it up. Enjoy.
jb
let's do the math. Here's the set up. Assume ;
1) the bucket when fully filled holds 1 cu yard.
2) time to scoop the bucket into the spoils is 10 seconds
3) time to back up, readjust the bucket and hit the pile a second time is also 10 seconds
4) time to raise the arms and dump the bucket is 10 seconds
5) the bucket when filled a second time goes from 3/4 yard to 1 yard.
6) travel time from the spoils to a dump truck is 5 seconds
7) travel from the dump truck to the spoils is 5 seconds
So... how much dirt can you move in an hour of dedicated focused work?
One cycle of fill, transport, dump and return is;
10 seconds fill time + 5 seconds transport + 10 seconds dump + 5 seconds return = 30 seconds.
120 of these cycles can be done in an hour. Each resulting in 1 yard of dirt moved or 120 yards total moved per hour.
How much is moved in an hour if a second scoop is needed?
One cycle to fill, top off, transport, dump and return is;
10 s fill time + 10 s top off + 5 s transport + 10 s dump + 5 s return = 40 seconds
There are 3600 seconds in an hour, so 3600/40 = 90 trips can be made moving a total of 90 yards of dirt per hour.
Pretty obvious that 120 is more than 90! So the old advice is right.
But is that the whole story? What if your bucket is only filled to 75% and YOU DON'T TOP OFF??
You still get the same 120 cycles per hour, but each bucket only holds 3/4yard. 3/4of 120 = 90 yards of dirt. So, there is no net gain in dirt moved. Still seems like the old advice is sound!
But is it right for us small guys that are not dumping into a dump truck parked close to the spoils pile? Hmmmm.... If we adjust the assumptions a bit we can find out!
let's do the math. Here's the modified set up. Assume ;
1) the bucket when fully filled holds 1 cu yard.
2) time to scoop the bucket into the spoils is 10 seconds
3) time to back up, readjust the bucket and hit the pile a second time is also 10 seconds
4) time to raise the arms and dump the bucket is 10 seconds
5) the bucket when filled a second time goes from 3/4 yard to 1 yard.
6) travel time from the spoils to the dump site is 30 seconds
7) travel from the dump site to the spoils is 30 seconds
One cycle of fill, transport, dump and return is;
10 seconds fill time + 30 seconds transport + 10 seconds dump + 30 seconds return = 80 seconds.
3600 seconds per hour / 80 seconds results in 45 of these cycles done in an hour. Each resulting in 1 yard of dirt moved or 45 yards total moved per hour.
How much is moved in an hour if a top off scoop is needed?
One cycle to fill, top off, transport, dump and return is;
10 s fill time + 10 s top off + 30 s transport + 10 s dump + 30 s return = 90 seconds
3600 / 90 = 40 cycles per hour or 40 yards moved.
Here's the important calculation! How many yards are moved if you DON'T TOP OFF?
You get the same 45 cycles per hour, but each one only yields 3/4 yard for 33.75 yards total moved per hour.
Perfect fill = 45 yards
2[SUP]nd[/SUP] scoop fill = 40 yards
Imperfect fill = 33.75 yards
Aha! As suspected, the advice we have all heard is certainly valid → when the transport time is short. But, if you are moving dirt with the tractor bucket even a modest distance, it pays to ensure the bucket is full.
Ok, this might be useless information -- but it was bugging me, so I had to post it up. Enjoy.
jb