No OSHA Standard Names Tree Spades. Here Is What Applies.
A tree spade combines a heavy machine, high-pressure hydraulics, ground that may hide utilities, and often a tree on a public road. OSHA does not have a standard written specifically for tree spades. Tree spade safety rests on general rules instead, and which ones apply depends on the work.
Construction falls under 29 CFR Part 1926, agricultural operations under Part 1928, and most other work (general industry) under Part 1910. Under 29 CFR 1928.21, most Part 1910 standards do not apply to agricultural operations. Whether a nursery job counts as agriculture is your safety officer’s call.
Every employer also carries the General Duty Clause: a workplace free from recognized hazards causing or likely to cause death or serious physical harm (29 U.S.C. 654(a)(1)). Requirements vary by state and job type, and your operator’s manual and your employer’s safety program govern. Use this with the manual for your Big John tree spade.
Before You Dig
Call 811 for Both Ends of the Move
Call 811 or use your state 811 center’s website a few business days before digging so buried utilities get marked. State law sets the waiting period. Before the blades touch soil, confirm that every notified utility has responded.
A move digs two holes, so request locates for the dig site and the planting site. The 811 program warns that erosion and root growth can shift buried lines. Ask the owner about lines a utility may not own, such as irrigation or lighting.
State laws generally bar mechanized equipment within 18 to 24 inches of a marked line; inside that tolerance zone, lines are exposed by hand or vacuum excavation. Measure from the blade ring, not the trunk. On construction jobs, 29 CFR 1926.651(b) requires the estimated location of utilities to be determined before excavating.
Look Up Before the Towers Open
An opened spade and the tree it lifts can reach overhead lines. In general industry, 29 CFR 1910.333(c)(3)(iii) requires equipment that can raise parts near energized lines to keep 10 feet of clearance, plus 4 inches for every 10 kV over 50 kV.
In construction, 29 CFR 1926.600(a)(6) sets 10 feet for lines of 50 kV or below, more above that, measured to any part of the machine or load. Both rules relax clearance for lines that are de-energized and grounded or guarded by insulating barriers, and for transit with the structure lowered; the construction rule’s transit allowance requires no load.
Treat every wire as energized until its owner confirms it is de-energized and visibly grounded. Assign a clearance spotter. After a contact, use the crane rule’s training model (29 CFR 1926.1408(g)): stay in the cab unless fire or another emergency forces you out, and keep everyone off the machine and load.
The same rule trains crews on three more points: the danger of touching the machine and the ground at the same time, the safest way off equipment that may be energized, and step potential, the charged ground around it. Include all three in your contact drill.
If fire forces you out, Mississippi State University Extension advises jumping clear with both feet together and hopping away with feet together. Otherwise, stay in the cab until utility workers de-energize the line and confirm it is safe to exit.
Walk the Site and the Route
Walk both sites and the path between them, looking for soft ground, slopes, curbs and irrigation heads. Big John’s truck-mounted tree spades use stabilizing pads for a wider base during a dig, which only helps if the ground under them holds.
Operator Training and Who Is Responsible
Training is the employer’s job. On construction work, 29 CFR 1926.21(b)(2) requires employers to instruct each employee in recognizing and avoiding unsafe conditions. In general industry, 29 CFR 1910.132(f) requires PPE training. Since no OSHA standard names tree spades, build your own course around your machine:
- The manuals and safety decals for the spade and the carrier
- Every control, plus the gate lock or transport lock
- Locates, tolerance zones, power line clearances and contact procedures
- The bystander zone and one set of hand signals
- Leak checks, pressure release and servicing
- Transport and tie-downs
Big John’s skid steer tree spade attachments have adjustable valve body speed, and Big John recommends slowing the spade down for new operators. When a new machine arrives, ask the factory to walk your operators through its controls and locks, and record who was trained and when.
Tree care firms may also follow ANSI Z133, Safety and Health Requirements for Arboricultural Operations, now in its 2026 edition and free to download for individual use from the International Society of Arboriculture. It is an industry standard, not an OSHA regulation; your safety officer decides whether it covers spade work.
PPE for Tree Spade Crews
PPE starts with a hazard assessment. In general industry, 29 CFR 1910.132(d) requires the employer to assess hazards, select PPE and certify the assessment in writing; on construction sites, 29 CFR 1926.95 requires PPE wherever hazards demand it. For spade work, expect the list to include:
- A hard hat, since limbs move during a dig
- Safety glasses, always when checking hoses
- Gloves, safety-toe boots and long pants
- Hearing protection and high-visibility clothing where noise or traffic call for them
Operating the Spade
Hold a Bystander Zone
Mark the zone before the first cut, covering the towers, gates and the arc the tree travels when lifted. Nobody stands inside the blade ring or beside an open gate while the hydraulics are live. If someone walks in, the operator stops. Use one signal person.
Respect Pinch Points and Locks
Closing blades, gate hinges and tower slides crush hands and feet. Never reach into the ring while the machine can move. Big John lists a hydraulic gate lock on models such as the Model 44 and Model 54; use yours exactly as the manual says.
Big John truck spades have tower steps for canopy access. Climb only when the manual allows it and the blades are stopped.
Treat Hydraulic Pressure as a Hazard
Big John lists pressure relief at 3,000 PSI on the 90D and 3,500 PSI on the 100D. Fluid at that pressure can penetrate skin through an invisible leak. Never run a hand along a hose to find a leak. Pass cardboard or paper over it, wearing eye protection and gloves.
Gloves will not stop a pinhole jet, and an injection may only sting at first. Get medical care immediately; delay can cost a finger or a hand.
Keep People Out of the Hole
Big John lists the 90D root ball at about 60 inches deep. On construction sites, 29 CFR 1926.652(a)(1) requires cave-in protection for anyone in an excavation unless it is entirely stable rock or, under 5 feet deep, a competent person finds no sign of a possible cave-in. Nobody climbs into a spade hole; flag open holes.
Skid Steer Spades: Carrier Basics
29 CFR 1926.602(a)(1) leaves specific rules for rubber-tired skid steers reserved, meaning OSHA has not written them, so manuals and NIOSH guidance carry the detail. NIOSH Publication 2011-128 says to operate the loader’s controls only from the seat, belted, never bypass safety devices, carry loads low, and travel straight up or down slopes, heavy end uphill.
NIOSH also says never exceed the manufacturer’s load capacity. Big John lists the Model 54 at 3,000 pounds plus a root ball of about 2,400 pounds, all ahead of the coupler; check that against your loader’s rated operating capacity using our skid steer tree spade buying guide.
Transporting the Tree and the Machine
Big John lists the 90D closed for transport at about 13 feet 6 inches tall and 8 feet 5.75 inches wide, before a tree is loaded. There is no federal height limit; states set their own. On the National Network, states must allow 102-inch widths (23 CFR 658.15); wider loads go through state permits.
A loaded tree can push past that width and your state’s height limit, so tie the canopy in; our guide to limb management attachments covers tree tyers. On a commercial motor vehicle, loads extending over 4 inches past the sides or 4 feet past the rear need red or orange fluorescent flags at least 18 inches square (49 CFR 393.87).
Cargo on a commercial motor vehicle must be secured so it cannot fall, or shift enough to affect stability (49 CFR 393.100). Big John’s D-series truck spades come with a hydraulic transport lock; engage it per the manual. Tie skid steers down at their tie-down points.
For a skid steer of 10,000 pounds or more on a commercial motor vehicle, 49 CFR 393.130 requires at least four tie-downs, with attachments completely lowered and secured.
Under 49 CFR 383.5 and 383.91, a single vehicle used in commerce with a GVWR or gross weight of 26,001 pounds or more is a Group B commercial motor vehicle for CDL purposes. A 16,760-pound 90D with an 11,800-pound root ball passes that before the truck is counted.
States may exempt drivers of some farm vehicles from CDL rules (49 CFR 383.3(d)). Your state licensing agency confirms whether that applies, and your state DOT handles oversize permits.
Servicing Safely
Stored energy is the servicing hazard: a raised spade, a charged circuit, hot fluid. In general industry, 29 CFR 1910.147 requires a lockout/tagout program where unexpected start-up or stored energy could injure someone, including relieving stored energy after lockout. It excludes construction and agriculture.
On construction work, 29 CFR 1926.600(a)(3) requires equipment held aloft by slings, hoists or jacks to be blocked or cribbed before anyone works under it, with controls in neutral, motors stopped and brakes set during repairs. The sequence looks similar either way:
- Lower the spade to the ground, or block anything that must stay raised.
- Shut off the engine and remove the key, or lock out.
- Relieve hydraulic pressure using the manual’s procedure.
- Never work under a part held only by a cylinder; on skid steers, use the lift-arm support.
- Let hot fluid cool before opening lines.
Routine fluid, leak and lubrication checks are covered in our tree spade maintenance tips and winter checklist. Big John has parts ready to ship the same day in most cases, and its parts and service team answers routine and preventive maintenance questions.
Printable Pre-Dig Checklist
Print this and keep a signed copy with each job file. It supplements your operator’s manual and safety program; it does not replace them.
| Check | What done looks like | Initials |
|---|---|---|
| 811 ticket | Ticket numbers for the dig and planting sites; every utility responded | |
| Utility marks | Blade ring plus tolerance zone clear of every mark | |
| Owner lines | Owner asked about irrigation, lighting and other buried lines | |
| Overhead lines | Nearest line identified; clearance plan and spotter assigned | |
| Ground and slope | Pad locations firm; slope within the manual’s limits | |
| Route | Height, width and weight checked against bridges, wires and turns | |
| Hydraulics | Fluid level checked; hoses checked with cardboard, not hands | |
| Locks | Gate lock or transport lock working | |
| Carrier | Seat belt, ROPS and interlocks working; load within rated capacity | |
| PPE | Crew wearing what the hazard assessment requires | |
| Bystander zone | Zone marked; signal person named | |
| Emergency plan | Line-contact steps briefed; nearest hospital known |
Tree Spade Safety: Common Questions
Does OSHA have a standard for tree spades?
No standard is written specifically for tree spades. OSHA applies Part 1926 to construction, Part 1910 to general industry and Part 1928 to agriculture, plus the General Duty Clause. Your safety officer should confirm which part covers each job.
How far must a tree spade stay from power lines?
On general industry and construction jobs, 29 CFR 1910.333 and 29 CFR 1926.600(a)(6) both set 10 feet for lines of 50 kV or less, and more at higher voltages. Treat every line as energized and ask the utility for the voltage.
Do I need to call 811 before digging with a tree spade?
Yes. 811 asks anyone planning to dig to request locates, and state law sets the waiting period. Request locates for both the dig and planting sites, and confirm every utility has responded.
Who is responsible for training tree spade operators?
The employer. On construction work, 29 CFR 1926.21(b)(2) requires employers to instruct employees in avoiding unsafe conditions. Base training on the spade and carrier manuals, and keep records.
What PPE should a tree spade operator wear?
Whatever the employer’s hazard assessment requires. For most spade work that means a hard hat, safety glasses, gloves, safety-toe boots and long pants, plus hearing protection and high-visibility clothing where needed.
Is lockout/tagout required when servicing a tree spade?
In general industry, 29 CFR 1910.147 applies wherever stored energy could cause injury. It excludes construction and agriculture, where rules such as 29 CFR 1926.600(a)(3) apply. Either way, lower or block the spade, shut off the engine and relieve pressure.