What is snubbing in trucking? Snub braking is a method of controlling a truck and trailer while descending grades, particularly those that are relatively long and somewhat steep. In terms of braking, this means that the brake pedal will require greater input to achieve the same vehicle braking force as the brake rotor/drums build heat.
What is snubbing on a road?
This braking technique is called "snubbing." When operating any commercial vehicle, do not ride the clutch, race the engine, change gears or coast while driving down the grade. At the bottom of the grade, be sure to cancel the 4-way flashers.
What is a snubbing unit?
The first snubbing unit was primarily designed to work in well control situations to "snub" drill pipe and or casing into, or out of, a well bore when conventional well killing methods could not be used.
What is snub braking on a truck?
Snub braking is a method of controlling a truck and trailer while descending grades, particularly those that are relatively long and somewhat steep. In terms of braking, this means that the brake pedal will require greater input to achieve the same vehicle braking force as the brake rotor/drums build heat. Click to see full answer.
What is snubbing and when is it necessary?
Snubbing is necessary when a kick is taken, since well kill operations should always be conducted with the drillstring on bottom, and not somewhere up the wellbore.
What is the snub braking technique?
0:002:33Mr. John Tutorial: Snub Braking - YouTubeYouTubeStart of suggested clipEnd of suggested clipAlright I'm gonna demonstrate snub breaking it's not breaking is when you do periodic breaking toMoreAlright I'm gonna demonstrate snub breaking it's not breaking is when you do periodic breaking to bring the speed. Down. I'm gonna do it at five miles an hour at a time forty-five down to 40.
How do you drive a downhill semi truck?
1:1013:16Mountain Driving Tips For Truck Drivers - Handle That Big Rig Like a ...YouTubeStart of suggested clipEnd of suggested clipJust go slow steady down the hill. Don't go too fast go a little on the slow side. Let the JakeMoreJust go slow steady down the hill. Don't go too fast go a little on the slow side. Let the Jake brake do the work just touch the brake pedal occasionally.
Why do truck brakes burn?
If an inexperienced or negligent tractor trailer driver uses his brakes down a long hill, instead of keeping his truck in low gear and at a low speed, the brakes – besides having no pressure from the compressor – can overheat which can cause them to lose contact with the drum.
What is the proper way to control your vehicle when descending a downhill grade CDL?
According to the CDL manual, brakes should be applied just hard enough to noticeably slow down. When they are slowed down to at least 5 mph below the posted legal/safe speed for trucks, they should release the brakes. When the speed increases again to the speed limit, they should brake down again.
What gear should you be in going downhill in a semi truck?
Descending a mountain: when driving your semi downhill, always use a gear that is lower than one used for cresting the mountain. If your truck has a Jake brake or an engine retarder, make use of it to restrict your speed within safe limits.
How do you stop a truck with no brakes?
1:122:32Can you stop the car without brakes ??? - YouTubeYouTubeStart of suggested clipEnd of suggested clipLet go of the accelerator. And just use the engine braking to slow down and if you can do it rightMoreLet go of the accelerator. And just use the engine braking to slow down and if you can do it right most of the time you wouldn't even have to use the brakes.
Why do trucks use runaway ramps?
Truck escape ramps are used as a traffic tool on steep, sustained grades to check high vehicle speeds in emergencies. The ramps use a combination of momentum-halting media like gravel or sand and an incline to bring runaway vehicles to a halt.
Why do trucks run away?
A runaway truck is a vehicle that has lost use of its brakes on a downhill slope. Large commercial trucks are more likely to suffer a brake malfunction due the size and weight of big rigs – especially when the brakes are put under stress by heavy use on steep declines such as those found on mountain passes.
Why do big rigs catch on fire?
The Reasons Why Commercial Trucks Catch Fire Mechanical failure or malfunction - 59% Electrical failure or malfunction - 13% Exposure fire - 4% Collision, overturn, or run over - 3%
Should you brake when going downhill?
Engine braking is a more effective way to reduce your speed while traveling downhill. MAT Foundry Group, a British manufacturer of automotive safety parts, says that when you take your foot off the accelerator, the airflow to the engine is restricted.
What is the best thing to do if you lose your brake power on a downhill?
Even if your power-assisted brakes fail, you can still usually apply braking power by pressing harder on the brake pedal. In some countries there are emergency escape lanes on long downhill stretches that vehicles that experience brake failure can use, but they are not everywhere.
How do you go down a steep hill in a truck?
Tips for driving down a steep hill Use the auxiliary brakes to help control the vehicle speed if required. - If you find you're in the wrong gear, stop the vehicle immediately and select the right gear before moving on. - Never attempt to descend a hill in neutral gear or with the clutch depressed.
What is a snubbing unit?
In essence, a snubbing unit is a hydraulic rig that can do everything a rig can do, plus it can perform under pressure in an under balanced live well state. This is especially critical to the operators in the Haynesville Shale, which is known for HPHT wells.
What are the components of a snubbing unit?
Components of a Snubbing Unit. One of the main components of a snubbing unit is the slip. Stationary and travelling slips are operated in sequence to grip the pipe as it is snubbed into the well. Typically, a minimum of four slip bowls are used in snubbing operations. Two slip bowls are designated for "pipe light" operations.
When was the snubbing unit invented?
In the 1920's, the need for a rig to work with pressures at surface drove the invention of the snubbing unit. The first snubbing unit was primarily designed to work in well control situations to "snub" drill pipe and or casing into, or out of, a well bore when conventional well killing methods could not be used.
What is pipe heavy?
Pipe heavy occurs when either enough pipe has been snubbed into the well bore and fluid weight inside of the pipe is greater than the snub forces acting against the pipe in the well bore. While snubbing into the hole, there is a transition point the tubular goes through from being pipe light, to pipe heavy.
Grouch Road Train Member
When I started in '63 the steady pressure was the way to go, that was before "jakes". After "jakes" , the "snub system" became the accepted and the best way to take a heavy load down a mountain.
gpsman Road Train Member
Controlled braking: Light (5-15psi), steady brake application combined with proper gear selection when descending a grade at your safe speed. This method was taught for years but is no longer recommended in the manuals. Done properly, it will not smoke your brakes.
Xcis Medium Load Member
Grade is irrelevant. You can apply <15lbs. (apparently) forever w/o smoking properly adjusted brakes.
otherhalftw Insignificant Otter
Since there seems to be more and more of you (at least or more than "half my age" and less than 1/5 my experience, that keep referring to the practice of "locking your brakes), which is putting the rig in an uncontrolled/semi-controlled skid.
double yellow Road Train Member
Since there seems to be more and more of you (at least or more than "half my age" and less than 1/5 my experience, that keep referring to the practice of "locking your brakes), which is putting the rig in an uncontrolled/semi-controlled skid.
Upright Medium Load Member
I just went done cabbage at 25 mph and only touched the brakes up top to slow it down from 55. I dont start slowing till I get to the vista lookout then downshift till your at the gear you need to be to decend. There are 3 warning signs that tell you at the top. Btw, there was a driver on the shoulder halfway down the hill with his brakes smoking.
Xcis Medium Load Member
Tonythetruckerdude: I never said that light steady pressure did not work. Okay?
What is cargo manifest?
Cargo Manifest —a shipping document that lists the cargo and/or passengers on a ship, aircraft, or commercial vehicle. Cargo Weight —the weight of freight being transported. Most 5-axle tractor trailers can haul over 40,000 pounds of cargo, but their gross vehicle weight is 80,000 pounds.
What is a brake chamber?
Brake Chamber —a sealed canister that houses the brake’s working parts. Brake chambers on heavy-duty trucks convert air pressure to mechanical pressure to slow the vehicle when the driver depresses the brake pedal.
Where is a truck dock?
Docks, or loading docks, are usually located at warehouses, production facilities, distribution centers and freight terminals. Dock Plate —large steel plates that cover the gaps between truck bodies or trailers when positioned in a loading dock.
Do trucking companies use dead head miles?
Not all companies use them. Dead Heading —driving a tractor and empty trailer to pick-up a load. In most instances dead head miles don’t generate revenue for trucking companies and owner operators, but company drivers may be paid their normal mileage rate for dead head miles. Traveling without a payload.
What is a snubbing rig?
Snubbing rigs are used for well completion and intervention operations where the pipe needs to be run into the live wells. Live wells are the wells under pressure. Similarly to coiled tubing, work string is pushed into the well to overcome well pressure forces.
What are the advantages of snubbing rigs?
Advantages of Snubbing Rigs. Can work on live wells – this eliminates the need to kill the well, makes operations cheaper and prevents damage to the formation caused by kill mud. Higher pump rates – bigger ID of the pipe allows higher pump rates than coiled tubing.
Why is snubbing pipe stiffer than coiled tubing?
This is possible because the pipe used for snubbing is much stiffer than coiled tubing. This also means that it takes much more force to buckle the pipe used for snubbing. This usually allows snubbing rigs to get deeper in the well than coiled tubing units.
How much weight can you lift on a snubbing rig?
Able to lift up to 50 lbs. First aid and H2S certificates. Driver’s license (Class 1 preferred)
What is the point where a pipe light becomes heavy?
The point where the pipe light becomes pipe heavy is called the balance point . When the pipe just starts to run into the well under pressure, pressure forces will try to push the pipe out of the well.
Does a snubbing rig rotate?
Ability to rotate the pipe – in situations where the pipe needs to be rotated, the snubbing rig has an advantage over coiled tubing or wireline. Higher set down force at the tool – more force is transferred to the bottom hole assembly in comparison to coiled tubing. This is possible because the pipe used for snubbing is much stiffer ...
Overview
See snubber for a device used to suppress ("snub") voltage transients in electrical systems
Snubbing is a type of heavy well intervention performed on oil and gas wells. It involves running the BHA on a pipe string using a hydraulic workover rig. Unlike wireline or coiled tubing, the pipe is not spooled off a drum but made up and br…
Rigup
A snubbing rigup is a very tall structure. It consists of a hydraulically powered snubbing unit, which provides the force on a pipe, above a string of multi-layered pressure control components.
At the top of the snubbing unit is the basket, which serves as the control post for the rigup. Below the basket are the hydraulic jacks, which power the pipe into and out of the hole. It consists of two mechanisms for applying force to the pipe in either direction. Each mechanism consists of trave…
Stripping the pipe
Unlike coiled tubing or wireline, where the wire or tubing is always the same diameter allowing for a single unmoving primary barrier (stuffing box or stripper), snubbing uses a pipe, which will have an enlarged collar at the connection between the joints. Therefore, the pressure control system must be able to accommodate this variable diameter. The stripping rams accomplish this. The first stage of lowering a collar through the stripping system is to close the lower rams so as to s…
Heavy-pipe and light-pipe
Because snubbing is normally done under pressure, initially, the weight of pipe in wellbore is less than the force due to the wellbore pressure. This is described as light-pipe: downward force is required on the pipe to force it in against resistance. Once a sufficient amount of pipe has been run into the hole, the weight becomes sufficient to overpower the wellbore pressure and the pipe naturally wants to fall in the hole; this is heavy-pipe. At this point, the snubbing mechanism is ch…
Risks
The more complex method of pressure control, as compared to coiled tubing and wireline, naturally invites more opportunity for things to go wrong. One such peril was seen in June 2007 on the Shearwater platform. Snubbing was being used to clean out large pebble, which had entered the well through a collapsed liner. While pulling out of hole, one stripping ram was not opened sufficiently and a collar on the pipe string caught on the ram. The excessive force applied to the …
Note
Not all Snubbing units are large and time consuming to rig up. In the Canadian oilfield many companies use small "Stand Alone" snubbing units which can be broken down and rigged up in less than 3hrs. These Units consist of 4 segments which can be placed onto 4 separate trucks. These 4 segments consist of the following:
PUMP TRUCK - The Engine of the truck is used to power the pump (which is a series of valves m…
Units structures and capacities
Units varies in strength, there are 95K, 120K, 150K, 170K, 225K, 340K, 460K, 600K The number indicates their working strength in pulling force, and 150K means the unit is capable of pulling maximal 150000 pounds. This is based on the hydraulic force acting on the size of the unit's piston size. Also are there more complex special built unit to find as the CSU 160 a special build rig assist …
See also
• Oil well
• Drilling rig
• Well intervention
• Blowout preventer
• Completion