Excavators: Power Shovel, Backhoe an Front Shovel (by Faisal VA and Karthik V)

A brief presentation on engineering excavators and their three basic types.

1. EXCAVATORS 1 Submitted by: Karthik V (MT15CTM006) Faisal V A ( MT15CTM004)

2. EXCAVATORS: An excavator has been defined as a power-driven digging machine, usually mounted on crawler tracks. The major types of excavators used in construction include hydraulically powered excavators and the members of the crane-shovel family. However, dozers and scrapers are also capable of excavating soil and rock. 2

3. HISTORY 1.FIRST APPEARED IN LATE 1700’S/EARLY 1800’S 2.IN 1990 HAD A LONG CONVENTIONAL COUNTER WEIGHT ON REAR END

4. 4

5. CRAWLER EXCAVATOR Crawler excavator runs on two endless tracks (chain wheel system). These types of excavators are used in hilly areas where risks of sliding of machinery are on the verge. Crawler type excavator has low ground pressure because of spreading of load on large area. Therefore, it is also used where soil support is weak.

6. 6 WHEEL EXCAVATOR Wheel excavator runs on wheels and are used for excavation and loading of dump trucks and most of the time it is only used for plain ground operations. Because of wheel, it is not suitable for hilly areas due to low grip value to the ground.

7. 7 POWER SHOVEL EXCAVATORS BACK HOE EXCAVATOR FRONT SHOVEL EXCAVATOR THREE TYPES...

8. POWER SHOVEL EXCAVATOR Long-lasting and useful class of earth moving equipment Capable of excavating all types of earth except hard rock Size of power shovel varies from 0.375-1.05m 3 It may be crawler mounted or wheel mounted shovels 8

9. 9 Crawler mounted shovel: Low speed Effective in unstable soil Wheel mounted shovel: Higher speed Effective only in firm ground

10. Power shovel efficiency depends on: Class of material Depth of cutting Angle of swing Job conditions Management conditions Size of hauling units Skill of the operator Physical condition of the shovel 10

11. 11

12. Applications: Suitable for close range work Capable of digging very hard materials & remove big boulders Used in digging in gravel banks , clay pits , digging cuts in road works , road-side berms etc . 12

13. Back hoe excavator Also known as hoe , back shovel & pull shovel Used to excavate below the natural surface on which it rests Hoes used to excavate trenches , pits for basemants & grading works Used to establish natural slopes 13

14. In strom drain and utility work the hoe can perform the trench excavation and can handle the pipe by eliminating a second machine There are special buckets for everything from light sand to hard rock digging 14

15. Parts of a back hoe excavator 15

16. 16

17. Ideal Production: Size of bucket (Q) Cycle time(T)=L t +S t + D t + R t Fill factor(F) (Table 9.1) Efficiency Factor(E) Height & Swing Factor (Table 9.2 ) Volume Correction V c Production ( lcy / hr ) =  

18. Applications: Suitable for digging below the machine level Effectively used to dress or trim the surface avoiding the use of manual effort for dressing the excavated surface 18

19. FRONT SHOVEL EXCAVATOR 19 Track system

20. Front excavator Used predominately for hard digging above track level and loading haul units Loading of shot rock will be a typical application Shovel is capable of developing a high break out force The material being excavated should be such that it will stand with a fairly vertical face 20

21. Front shovel excavator High excavation rate due to unique front shovel and side tip operation Prolec laser system enables excavation to a more accurate level – resulting in quicker excavation rates while reducing the chance of over-digging 21

22. Improved track quality due to the excavation action (pushing into spoil rather than pulling it back) Fewer machine controllers on site meaning less risk and safer operations 22

23. 23

24. 24

25. 25

26. Factors afecting shovel excavators are: Class of material Height of cut Angle of swing Size of houling units Operator skill Physical conditions of the shovel 26

27. Calculating shovel production Four elements in the production cycle of a shovel are: Load bucket Swing the load Dump load Return swing

28. Ideal Production: Size of bucket (Q) Cycle time(T)=L t +S t + D t + R t Fill factor(F) (Table 9.1) Efficiency Factor(E) Height & Swing Factor (Table 9.2 ) Production ( lcy / hr ) =  

29. 29 Thank you...