Manta Ray & Sting Ray Earth Anchors

manta ray

Manta Ray & Stingray structural Properties and Capacities

Manta Ray & Stingray Anchor Structural Properties :

Anchor
Structural Safety
Factor 2:1
Recommended Anchor Rod
Weight
per
Each
Manta Ray
Diameter *
Part
Number
MR-68
2.5 kips
(11 kN)
3/8″
(10 mm)
B8S-03
1 lbs.
(0.45 kg)
MR-88
5 kips
(22 kN)
1/2″
(12 mm)
B8S-04
2.2 lbs.
(1 kg)
MR-4
8.5 kips
(36 kN)
#6 – 3/4″
(20 mm)
R61-06
4.7 lbs.
(2.1 kg)
MR-3
10 kips
(45 kN)
#6 – 3/4″
(20 mm)
R61-06
6 lbs.
(2.7 kg)
MR-2
20 kips
(89 kN)
#6 – 3/4″
(20 mm)
R61-06
10 lbs.
(4.5 kg)
MR-1
20 kips
(89 kN)
#6 – 3/4″
(20 mm)
R61-06
12 lbs.
(5.4 kg)
MR-SR
20 kips
(89 kN)
#6 – 3/4″
(20 mm)
R61-06
21 lbs.
(9.5 kg)
MK-B
20 kips
(89 kN)
#6 – 3/4″
(20 mm)
R61-06
85 lbs.
(38.5 kg)
Sting Ray
S.F.
Diameter *
Part Number
Weight
SR-1
45.5 kips
(198 kN)
#9 – 1-1/8″
(28 mm)
R61-09
47 lbs.
(21.3 kg)
SR-2
50 kips
(223 kN)
#9 – 1-1/8″
(28 mm)
R61-09
66 lbs.
(30 kg)
SR-3
50 kips
(223 kN)
#9 – 1-1/8″
(28 mm)
R61-09
91 lbs.
(41.2 kg)

Anchor Rods are fully threaded and can be field cut and coupled.
* Anchor rod lengths: R61-06 & R61-09 – Up to 50 feet uncoated
B8S-03 & B8S-04 – Up to 20 feet
Recommended: Galvanized rods should be cut to size prior to galvanizing to insure good nut fit.Manta Ray Working Capacities in Listed Soils :

Common Soil Type
Description
Typical Blow
Count “N” per
ASTM-D 1586
MR-68
MR-88
MR-4
MR-3
MR-2
MR-1
MR-SR
MK-B
Peat, organic silts ; inundates silts fly ash
0 – 5
N.A.
0.2-0.9 kips
(0.9-4 kN)
(4, 6)
0.3-1.5 kips
(1.3-7 kN)
(4, 6)
0.8-3 kips
(3.5-13 kN)
(4, 6)
2-5 kips
(9-22 kN)
(4, 6)
3-8 kips
(13-37 kN)
(4, 6)
4-12 kips
(18-53 kN)
(4, 6)
6-16 kips
(27-71 kN)
(4, 6)
Loose fine sand; alluvium; soft-firm clays; varied clays; fills
4 – 8
0.4-0.8 kips
(1.8-3.5 kN)
(4, 6)
0.9-1.5 kips
(4-7 kN)
(4, 6)
1.5-2.5 kips
(7-11 kN)
(4, 6)
3-5 kips
(13-22 kN)
(4, 6)
5-8 kips
(22-36 kN)
(4, 6)
8-12 kips
(36-53 kN)
(4, 6)
9-14 kips
(40-62 kN)
(4, 6)
13-20 kips
(58-89 kN)
(4, 6)
Loose to medium dense fine to coarse sand; firm to stiff clays and silts
7 – 14
0.75-1.3 kips
(3.5-6 kN)
(4)
1.5-2.5 kips
(7-11 kN)
(4)
2.5-4 kips
(11-18 kN)
(4)
5-8 kips
(22-36 kN)
(4)
7-10 kips
(31-44 kN)
(4)
10-15 kips
(44-67 kN)
(4)
14-18 kips
(62-80 kN)
(4)
20 kips
(89 kN)
(4)
Medium dense coarse sand and sandy gravel; stiff to very stiff silts and clays
14 – 25
1-1.5 kips
(5-7 kN)
(4)
2-3 kips
(9-13 kN)
(4)
3.5-4.5 kips
(16-20 kN)
(4)
7-9 kips
(31-40 kN)
(4)
9-12 kips
(40-53 kN)
(4)
15-20 kips
(67-89 kN)
(4)
18-20 kips
(80-89 kN)
(4)
20 kips
(89 kN)
(2, 4)
Medium dense sandy gravel; very stiff to hard silts and clays
24 – 40
1.5-2 kips
(7-9 kN)
(4)
3-4 kips
(13-18 kN)
(4)
4.5-6 kips
(20-25 kN)
(4)
9-10 kips
(40-45 kN)
(4)
12-18 kips
(53-80 kN)
(4)
18-20 kips
(80-89 kN)
(2, 4)
20 kips
(89 kN)
(2, 4)
20 kips
(89 kN)
(2, 3, 4)
Dense clays, sands and gravel; hard slits and clays
35 – 50
2-2.5 kips
(9-11 kN)
(4)
4-5 kips
(18-22 kN)
(4)
6-8.5 kips
(27-36 kN)
(4)
10 kips
(45 kN)
(2, 4)
15-20 kips
(67-89 kN)
(2, 4)
20 kips
(89 kN))
(2, 4)
20 kips
(89 kN)
(2, 3, 4)
20 kips
(89 kN)
(1, 3)
Dense fine sand; very hard silts and clays
45 – 60
2.5 kips
(11 kN)
(2, 3, 4)
5 kips
(22 kN)
(2, 3, 4)
8.5 kips
(36 kN)
(2, 3, 4)
10 kips
(45 kN)
(2, 3, 4)
20 kips
(89 kN)
(2, 4)
20 kips
(89 kN)
(1, 3, 4)
20 kips
(89 kN)
(1, 3)
20 kips
(89 kN)
(1, 3, 5)
Very dense and / or cemented sands; coarse gravel and cobbles
60 – 100+
2.5 kips
(11 kN)
(1, 3)
5 kips
(22 kN)
(1, 3)
8.5 kips
(36 kN)
(1, 3)
10 kips
(45 kN)
(1, 3)
20 kips
(89 kN)
(1, 3, 4)
20 kips
(89 kN)
(1, 3)
20 kips
(89 kN)
(1, 3, 5)
20 kips
(89 kN)
(1, 3, 5)
1 – Drilled hole required to install.
2 – Installation may be difficult. Pilot hole may be required.
3 – Holding capacity limited by working load of anchors.
4 – Holding capacity limited by soil failure.
– Not recommended in these soils.
6 – Wide variation in soil properties reduces prediction accuracy.
A minimum of 2:1 Safety Factor is recommended.
Use this chart for estimation only, true capacity must be tested with anchor locker.
The values in chart are based on minimum 3′ embedment depth for models MR-68 & MR-88 and 7′ for Models MR4 thru MK-B. (Minimum overburden depth is 4′.) Field testing is recommended for other possible depths.

Stingray Working Capacities in Listed Soils :

Common Soil Type
Description
Typical Blow
Count “N” per
ASTM-D 1586
SR-1
SR-2
SR-3
Peat, organic silts; inundates silts fly ash
0 – 5
N.A.
N.A.
N.A.
Loose fine sand; alluvium; soft-firm clays; varied clays; fills
4 – 8
13-19 kips
(58-82 kN)
(4, 6)
19-28 kips
(85-125 kN)
(4, 6)
24-37 kips
(107-165 kN)
(4, 6)
Loose to medium dense fine to coarse sand; firm to stiff clays and silts
7 – 14
16-24 kips
(72-107 kN)
(4)
27-36 kips
(120-160 kN)
(4)
37-48 kips
(165-214 kN)
(4)
Medium dense coarse sand and sandy gravel; stiff to very stiff silts and clays
14 – 25
24-32 kips
(107-142 kN)
(4)
31-48
(138-214 kN)
(4)
48-50 kips
(214-223 kN)
(4)
Medium dense sandy gravel; very stiff to hard silts and clays
24 – 40
29-41 kips
(129-182 kN)
(4)
46-50 kips
(205-223 kN)
(4)
50 kips
(223 kN)
(4)
Dense clays, sands and gravel; hard slits and clays
35 – 50
39-45.5 kips
(173-198 kN)
(4)
50 kips
(223 kN)
(2, 4)
50 kips
(223 kN)
(2, 3, 4)
Dense fine sand; very hard
silts and clays
45 – 60
45.5 kips
(198 kN)
(2, 4)
50 kips
(223 kN)
(2, 4)
50 kips
(223 kN)
(2, 3)
Very dense and / or cemented sands; coarse gravel and cobbles
60 – 100+
45.5 kips
(198 kN)
(1, 3)
50 kips
(223 kN)
(1, 3)
50 kips
(223 kN)
(1, 3, 5)
1 – Drilled hole required to install.
2 – Installation may be difficult. Pilot hole may be required.
3 – Holding capacity limited by working load of anchors.
4 – Holding capacity limited by soil failure.
– Not recommended in these soils.
6 – Wide variation in soil properties reduces prediction accuracy.
A minimum of 2:1 Safety Factor is recommended.
Use this chart for estimation only, true capacity must be tested with anchor locker.
The values in chart are based on minimum 3′ embedment depth for models MR-68 & MR-88 and 7′ for Models MR4 thru MK-B. (Minimum overburden depth is 4′.) Field testing is recommended for other possible depths.