Pond Boss Forums INTRO Common Pond Q&A (archives) USDA Agriculture Handbook # 590 "Ponds - Planning, Design, Construction"

Machines Build Specifically for Compacting Soils - Mainly Clay Like Soils Used for Pond Building.
Material was gleaned from the Internet

The sheepsfoot roller is most effective for compaction of plastic soils like clay or silt, according to Bomag Americas, a leading roller manufacturer. The tamping foot, which combines the advantages of a vibratory roller with a sheepsfoot. A sheepsfoot compacts from the bottom of each lift towards the top. High contact pressures cause the feet to penetrate through the loose material and actually compact the material directly with the foot tip. A number of passes are required with a sheepsfoot roller because of the small area compacted by each foot.

The pads on sheepsfoot drums penetrate through the top lift and actually compact the lift below. When a pad comes out of the soil, it kicks up or fluffs the material. The result is a loose layer of material on top. When more fill is spread, the top lift will be fluffed and the previous layer will be compacted. A sheepsfoot compactor truly compacts from the bottom up. Using a sheepsfoot compactor has one definite benefit. Because the top lift of soil is always being fluffed, the process helps aerate and dry out wet clays and silts.

The sheepsfoot roller is highly demanded for compaction of plastic soils like clay or silt. These rollers penetrate through the loose soil material and compact the material directly with the foot tip. Pneumatic-tired rollers compact the soil from the top of the lift downward. The principle of working of vibratory rollers is by rearranging the soil from dynamic forces produced by the drum hitting the ground. A tamping foot roller also known as pad roller has feet, or pads, compacting the soil by penetrating deep into it and tilt the soil from the bottom to the top for uniform density. All these soil rollers work in accordance to their combination of vibration speed and foot shapes, thereby compacting the soil by producing a kneading effect.

Vibratory compactors work on the principle of particle rearrangement to decrease voids and increase density and load bearing strength. They come in two types: smooth drum and padfoot drum. For increased versatility, smooth drum compactors can be equipped with optional padfoot shell kits, which allows the use of smooth drum rollers in padfoot applications, albeit with limited performance.

Sheepsfoot roller contractors used for varied soil and aggregate compactors. A sheepsfoot roller is most popular as this type of roller can compact the soil directly beneath the foot tip. Because of the high compaction speed and high pressure applied to the soils, it is very useful in the construction of both small and big dams.
CHARACTERISTICS SHEEPSFOOT ROLLER:
1. the coverage area of the ground is less. 8-12 % ground coverage under the lugs on the drum.
2. Ruler pressure up to 1400 to 7000 kpa.
3. normally at speeds of work Sheepsfoot roller from 6-10 km/h. (3-6 mph)
4. The roller pressure on the feet may be increased by filling the drum with some wet external other material or sand.
5. Sheepsfoot roller Mostly used for cohesive soils such as heavy clays and silty clays except for sandy soil.
6. Compaction efforts are kneading and static weight.
7. The thickness of the compacting layer is kept a minimum of 50 mm(2inches) or more, which depends on the length of the foot.

Tamping Foot Compactors
Tamping foot compactors are high-speed, self-propelled, non-vibratory compactors. They usually have four padded steel wheels and are equipped with a dozer blade. Their pads are tapered with a rectangular face.
Tamping foot compactors compact from the bottom of the lift to the top. Because the pads are tapered, they can walk out of the lift without fluffing the soil. Therefore, the top of the lift is also being compacted and the surface is relatively smooth and sealed. Tamping foot compactors are capable of speeds in the 16-32 km/h (10-20 mph) range, but they typically operate in the 10-15 km/h (6 to 10 mph) range.
Generally, two to four cycles (4 to 6 machine passes) will achieve desired densities in 200- to 300-mm (8- to 12-in.) lifts although four cycles may be needed in poorly graded plastic silt or very fine clay. Tamping foot compactors are effective on all soils except clean sand.

Tamping foot compactors leave a fairly smooth, sealed surface so hauling units are able to maintain a high speed when traveling over the fill. Also, since dozer-equipped tamping compactors do both spreading and compacting, the contractor may be able to reduce the number of track-type spreaders.

Tamping foot compactors are best suited for large projects. They need long, uninterrupted passes to build up speed that generates high production. On lifts greater than 300-mm (12-in.) thick, tamping foot compactors are about two to three times more productive than single-drum vibratory compactors.

Pad foot/Slash Presser rollers are similar to sheep foot roller. However, they have lugs on their cylinders, which have larger area than the feet of sheep foot rollers.
They are also sometimes termed as tamping rollers having static weight in the range of 15 to 40 tons. They can achieve more degree of compaction than sheep foot rollers. They also operate on high speeds and can break down large lumps of soil. They are best suitable for compacting cohesive soils.

Padfoot rollers generate static pressure, vibration, and impact on the materials. However, they also generate manipulative force. This allows for uniform compaction during the entire process.
Padfoot compactors have tapered pads that penetrate and compact the soil to build up the soil’s strength. Gravity and the vibrations compact the material from the top down.

Padfoot drum machines expand the material range to include soils with more than 50 percent cohesive material and a greater percentage of fines. When the pad penetrates the top of the lift, it breaks the natural bonds between the particles of cohesive soil and achieves better compaction results. The pads are involuted to walk out of the lift without fluffing the soil and tapered to help them stay clean.