Why are dozer push arms sometimes inside or outside the tracks?

[Cartoondude135]

Bear with me, I'm not a dozer guy, so I know nothing about dozers. But I want Astragon to implement this into Construction Simulator 2022.

To illustrate, let's take this template from a brochure
and this from an equipment auction site

See how the "push arms" (the dozer equivalent of lift arms of a front loader) are designed to be installed inside the tracks instead of outside like most dozers? What's the name of this configuration? This is the one dozer push arm configuration I favor the most than the push arms on the outside because the only theory I can think up here is it allows me to clean the tracks 10 times easier than if I had the dozer's push arms outside the tracks. Especially at the garbage stations.

Also, on snowy days, the dozer can act as a makeshift snow plough to push the snow to a specific side due to it's fully agile hydraulic articulating blade. The sweeps also make it more resilient to overhead fall hazards.

 

[Shimmy1]

PAT (power angle/tilt) blades virtually require inside push beam to provide a place for a pivot, and the cylinder rams.

 

[John Shipp]

The configuration you like the look of (2nd picture) as Shimmy says is a Power Angle Tilt blade (PAT blade). It has central pivot point and can be angled and tilted hydraulically while on the move, hence the central pivot and inner push arms giving it the space to angle one side or other. A 6-way PAT is very common in construction projects nowadays with it's ability to trim grade and adjust on the go. Not necessarily easier to keep clean as mud and crap can get jammed in between the engine panels, frame, and track frames.

The push arms on the outside of the tracks is a more robust design, more suitable for pushing out rocks and stumps where a PAT blade could get damaged if care not taken. Typically with a straight (S) blade, or a SU blade it can have a tilt feature on the go, but doesn't angle side to side.
See a lot of this design on landfill sites, for spreading dumped loads and often pushing trucks out as well.

A sort of in between design half way between the two has outside push arms that go round the front of the machine in a continuous piece, the blade is then pinned to this and can be manually unpinned and the angle changed from one side to other or straight. Not so common now, possibly PAT blades have done away with them? Someone might know, can't say I've seen on any recent dozers.

You can get full sweeps and guard packages on either set up.

 

[CM1995]

To break it down into laymen terms -

The first dozer is used more for mass earth moving. The push arms for the blade being on the outside provide more support for a larger blade but not as much articulation

The second dozer is used more for fine grading and finish work since the blade is a " 6 way" meaning it can move/articulate in 6 different positions to finish grade.

 

[henry.45]

Thank you for the detailed explanation! It's fascinating to learn about the different designs of bulldozer blades and their use cases.

The configuration you like the look of (2nd picture) as Shimmy says is a Power Angle Tilt blade (PAT blade). It has central pivot point and can be angled and tilted hydraulically while on the move, hence the central pivot and inner push arms giving it the space to angle one side or other. A 6-way PAT is very common in construction projects nowadays with it's ability to trim grade and adjust on the go. Not necessarily easier to keep clean as mud and crap can get jammed in between the engine panels, frame, and track frames.

The push arms on the outside of the tracks is a more robust design, more suitable for pushing out rocks and stumps where a PAT blade could get damaged if care not taken. Typically with a straight (S) blade, or a SU blade it can have a tilt feature on the go, but doesn't angle side to side.
See a lot of this design on landfill sites, for spreading dumped loads and often pushing trucks out as well.

A sort of in between design half way between the two has outside push arms that go round the front of the machine in a continuous piece, the blade is then pinned to this and can be manually unpinned and the angle changed from one side to other or straight. Not so common now, possibly PAT blades have done away with them? Someone might know, can't say I've seen on any recent dozers.

You can get full sweeps and guard packages on either set up.

 

[chidog]

Inside for narrow blade and limit dozer width.
Outside for larger wide blade, and better blade support.

 

[Welder Dave]

For stumping, pushing scrapers and other super heavy duty jobs outside push arms are much stronger. A guy that cleared some bush for me got a good deal on a JD 850J WLT because it had a bad crack in the C frame of the 6 way dozer. He figured it was probably from digging out stumps with the corner of the blade.

 

[henry.45]

When it comes to heavy-duty tasks like stump removal and pushing scrapers, outside push arms are the way to go because of their added strength. I recall a story about someone who bought a JD 850J WLT at a discounted price due to a cracked C frame on the 6-way dozer blade. The seller suspected that the damage was caused by using the blade's corner to dig out stumps, which highlights the importance of using the right equipment for the job.

 

[Welder Dave]

???

 

[stinky64]

Ole' henry = AI, Check the rest of it's responses. BS meter on Full Tilt..

 

[Tinkerer]

When it comes to heavy-duty tasks like stump removal and pushing scrapers, outside push arms are the way to go because of their added strength. I recall a story about someone who bought a JD 850J WLT at a discounted price due to a cracked C frame on the 6-way dozer blade. The seller suspected that the damage was caused by using the blade's corner to dig out stumps, which highlights the importance of using the right equipment for the job.

Sorry, you are quite wrong on pushing scrapers.
Many tractors have been built with blade arms on the inside for added strength.
I guess you have never seen Cat D9's from back in the 1960's and newer, until they quit making them and introduced the D10's and D10T's.
The blades would pivot from the bottom pins and had huge springs in them to absorb the shock when it contacted a scraper stinger or the push block on another tractor.
We used to triple up the push Cats when the scrapers were in really hard material.

 

[Nige]

Ah the good old days. Double or Triple-pushing 657s with D9Gs.

 

[willie59]

And that Cat "Sunbrella", they were the real deal back then.

 

[Nige]

Or a more modern take on the subject pushing with a high-track. The push arms are still the same though.......

 

[willie59]

651 scrapers I presume.

 

[Nige]

651 scrapers I presume.

Yup. No engine at the back that's why they need so much push power.

 

[willie59]

Yup. No engine at the back that's why they need so much push power.

Burning diesel in it's finest fashion.

 

[Welder Dave]

Sorry, you are quite wrong on pushing scrapers.
Many tractors have been built with blade arms on the inside for added strength.
I guess you have never seen Cat D9's from back in the 1960's and newer, until they quit making them and introduced the D10's and D10T's.
The blades would pivot from the bottom pins and had huge springs in them to absorb the shock when it contacted a scraper stinger or the push block on another tractor.
We used to triple up the push Cats when the scrapers were in really hard material.

I originally said that but I was referring to 6 way dozers not being the best for pushing scrapers. I wasn't considering dozers that were specifically set up for pushing scrapers. I've seen the old push dozers with a much smaller push plate that is inside mounted. I remember the county was using a D6N to push a D8H with a cable scraper and they had to be careful because a 6 way dozer isn't ideal for pushing scrapers and can be damaged.