Drawing of a viewing pit for trucks: dimensions, schemes and step-by-step construction

If you are planning to build a viewing hole for kamaz, MAZE or Scania with a wheel formula 6×4, the standard dimensions of the car pit will not fit - the minimum width should be at least 2.2 m m m m mThe depth is calculated from ground clearance (clearance) + 20-30 cm for comfortable access to the transmission. An error in the calculations will lead to the fact that the wheels of the truck will rest against the walls, and the master will not be able to reach the gearbox or gearbox of the rear axle. In this article - verified drawings of observation pits for trucks, taking into account SNIP 2.07.01-89* practical experience in construction in private garages and car service stations.

The first thing to consider is truck-weight. For example, Volvo FH16 with a total weight of 44 tons requires a reinforced foundation (concrete M300 with a rod reinforcement of 12-14 mm), while for GAZON NEXT (up to 10 tons) is enough brand M200. The second critical parameter is angularity: if the pit is too short, the front overhang of the truck will cling to the edge when entering. The optimal ratio of the pit length to the length of the car is 1:1.2 (for example, for a 12-meter truck, the pit should not be shorter than 14.4 m).

Requirements for a viewing pit for trucks according to SNiP

I agree. SNIP 2.07.01-89* (p. 6.31) and GOST 21.204-2012Viewing pits for freight transport are classified as "high-risk structures". This means that the project must be coordinated with local technical supervision authorities if the pit is deeper than the surface. 1.8 m m or intended for vehicles of a mass greater than 12 tons. The main regulatory requirements:

• 📏 Minimum width: 0.9 m for minibuses (e.g. Ford Transit), 2.2-2.5 m for 4x2 and 6x4 wheelbase trucks.
• 🔧 Depth.: clearance of the car + 20 cm (for MAZ-5336 with clearance of 320 mm - a pit of 50-55 cm.
• 🚧 The slope of the ramp: no more than 25° (optimally 15-20° for heavy trucks).
• ⚡ Electrical safety: lighting only 12V, sockets with RCD, cables in corrugated.
• 🛡️ Fences: sidebars 10-15 cm high along the perimeter of the pit.

Special attention is paid to ventilation. In closed garages, a supply and exhaust system with a performance of at least 180 m3/h (for a hole 2×6 m). In the absence of ventilation, the concentration of carbon monoxide (CO) from a working diesel engine exceeds the MPC by 5-7 times after 10 minutes.

⚠️ Attention.If the pit is built in a garage with sandy or clay soil, waterproofing It's mandatory. The rise of groundwater in the spring can lead to flooding. Use ruberoid in 2 layers + penetrating waterproofing (for example, penetron).

Typical dimensions of observation pits for popular trucks

The size of the pit depends on wheelbase, clearance and frame-frame. Below is a table with parameters for common models of freight transport (data are relevant for modifications 2018-2026):

Model truck.	Wheelbase (m)	Clearance (mm)	Recommended pit width (m)	Recommended depth (m)	Minimum pit length (m)
KAMAZ-5320	3.34 + 1.32	290	2.2	0.5–0.6	7.5
MAZ-5336	3.9 + 1.4	320	2.3	0.55–0.65	8.2
Scania R420	3.7-6.7 (depending on the modification)	310	2.4	0.5–0.7	9.0
Volvo FH16	3.9–6.1	340	2.5	0.6–0.75	9.5
GAZON NEXT	3.75	270	2.0	0.45–0.55	6.5

For truck-truck (e.g., DAF XF or Mercedes Actros) the length of the pit shall exceed the length of the frame by 1.5–2 mto provide access to the fifth wheel and fuel tanks. If the garage is limited in length, use it. P-pit with a notch under the front axle.

Drawings of observation pits: schemes and marking

Below are the following: 3 standard drawings Viewing pits for trucks with indication of critical dimensions. The schemes are adapted to the most common cases:

1. A rectangular pit for single trucks (e.g., KAMAZ-6520):

• 📌 Length: 8 m (for wheelbase up to 5.5 m).
• 📌 Width: 2.3 m (wheel distance 1.9 m + 0.4 m margin).
• 📌 Depth: 0.6 m (clearance 300 mm + 30 cm).
• 📌 Rappel: length 1.5 m, slope 15-18 °.

2. Elongated pit for trucks and road trains (e.g., Volvo FH with trailer):

• 🚛 Length: 15 m (12 m - tractor + 3 m - trailer).
• 📏 Width: 2.5 m (for gable wheels).
• 🔨 Depth: 0.7 m (clearance 340 mm + 36 cm).
• 🔄 U-shaped: recess under the front axle 1×2 m.

For dump-car (e.g., BelAZ-7555) a pit with reinforced walls 25-30 cm thick and additional stiffness ribs from the channel No. 10. The drawing of such a pit shall include:

• 🏗️ Deepening under the rear axle (depth +20 cm).
• 🔩 Anchor bolts for fastening removable ladders.
• 💡 LED tape around the perimeter (12V, moisture protection IP67).

How do you calculate the slope of the ramp?

Formula: tan(α) = H/L, where α is the angle of inclination, H is the depth of the pit, L is the length of the ramp. For trucks, the optimal angle is 15-20° (tan(15°) ≈ 0.27). Example: if the depth of the pit is 0.6 m, then L = 0.6 / 0.27 ≈ 2.2 m.

Step-by-step instructions for the construction of an observation pit

The construction of a truck pit consists of 7 stages. Sequence disturbance (e.g. pouring concrete without waterproofing) will result in cracks or drawdown after 1-2 years. Use this guide as a checklist:

1. Check the groundwater level (if above 2.5 m - you need a drainage system)

2. Clean the area of debris and remove the top layer of soil (15-20 cm)

3. Mark the contours of the pit with pegs and cord (check diagonals!)

4. Prepare the tool: shovels, wheelbarrow, concrete mixer, vibrator for concrete

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1. Earthworks:

Dig a hole in the hole. 20cm and 10cm deep. design sizes - this space will be occupied by waterproofing and screed. For loose soils (sand, soup), make the walls with a slope of 5-10 ° in order to avoid falling. If the depth of the pit is more than 1.5 m, use wall-holding boards and struts.

2. Waterproofing and drainage:

Order of layers (bottom up):

1. Throated crushed fraction of 20-40 mm (layer 10 cm).
2. Sand (a layer of 5 cm, spilled water and rammed).
3. ruberoid Technoelast in 2 layers with a cover of 15 cm (glue with bitumen mastic).
4. Geotextile (if groundwater is close)

To drain water, install drainage pipes (diameter 100 mm) at the corners of the pit with a slope of 2 ° towards the collector or septic tank.

3. Concrete reinforcement and pouring:

Use it. rebar with a cell of 15×15 cm from a rod of 12–14 mm (for trucks over 20 tons – 16 mm). The mesh should be 5 cm away from the walls (use plastic fixers). Pour concrete in layers of 20-30 cm with vibration to remove bubbles. Concrete stamp:

• 🚛 Up to 10 tons: M200.
• 🚚 10–30 tons: M250–M300.
• 🛻 Over 30 tons: M350 with fibre.

⚠️ Attention.: If the pit is being built in a region with frosts below -20°C, add to the concrete frost-additive (e.g., Plasticizer C-3) and insulate the walls with polystyrene foam (5 cm thick).

Mistakes in construction and how to avoid them

Even experienced professionals make mistakes that lead to pit-fall, crack or flooding. Here. Top 5 critical misses And how to prevent them:

• 🔨 The ramp's too steep. The truck is clinging to the front bumper. Decision: angle not exceeding 15° for heavy machinery.
• 💧 Lack of waterproofing In spring, the pit turns into a pool. Decision: ruberoid + penetrating insulation.
• 📏 Wrong width The wheels are against the walls. Decision: width = wheel spacing + 40 cm.
• ⚡ Lighting 220V without protection Risk of electric shock. Decision: only 12B with transformer.
• 🏗️ Savings on fittings Cracks in a year. Decision: grid 15×15 cm, rod 12–14 mm.

Another common problem is ventilator. The hole without air exchange accumulates CO (Carbon monoxide) and fuel vapor. Minimum requirements:

• 🌬️ Supply pipe: diameter 150 mm, output at 0.3 m from the floor.
• 🌬️ Exhaust pipe: 200 mm diameter, exit under the ceiling of the garage.
• 🔌 Fan: capacity from 150 m3/h (e.g. Soler & Palau TD-160).

Additional equipment for the observation pit

The base pit is just the beginning. For full maintenance of the truck will require:

Equipment	Appointment	Recommended models	Cost (2026)
Hydraulic lift	Lifting bridges to replace tires	Nussbaum PL-5T, Ravaglioli T522	180,000 rubles
Mobile jack	Local frame lift	Zinko 20T, Norco 74052	45,000 rubles
LED spotlight	Lighting of hard-to-reach areas	Feron PL-100, Ecolight LED-50W	3,500 rubles
Toolbox	Storage of keys and devices	Keter Masterloader, Stanley FatMax	8,000 rubles
compressor	Blowing the parts, pumping the tires.	Fubag Air Master Kit, Quattro Elementi KM 50-270	22,000 rubles

For diagnostics (e.g., Scania or Mercedes Actros) a protocol-compatible scanner will be required J1939 (e.g., Launch X431 V+ or Bosch KTS 570). If you plan to work with pneumosystemAdd connections to the pit to connect compressed air (pressure at least 8 bar).

Maintenance and care of the observation pit

To make the pit work 10 years. Without repair, follow these rules:

• 🧹 Cleaning.Remove oil and dirt from the floor 1 time per month (use sandblasting or detergent) Liqui Moly Bremsen-Reiniger).
• 🔧 Checking cracks: Check the walls in the spring after snow melts. Cracks wider than 0.5 mm, fill with epoxy resin.
• 💡 Electrician.Check the insulation of the cables 2 times a year (Multimeter in mega-ohmmeter mode).
• 🌬️ Ventilation: Clean the fan filters every 6 months.
• 🛠️ Tool.Keep keys and jacks in sealed drawers (the moisture in the pit is higher by 30–40%).

If the pit is used for truck-washing- Of course:

1. Install. fat-retractor (e.g., Ecoline Zhu-0.5) for oil collection.
2. Cover the floor. polyurethane filler floor 3-5 mm thickness for protection against chemistry.
3. Use it. steam-generator water under pressure (less risk of corrosion)

⚠️ Attention.If you've appeared in the hole hydrogen sulfide (rotten eggs), stop working immediately - this is a sign of a leak of sewer gases. Check the drainage pipes for depressurization.

FAQ: Frequent questions about truck viewing pits

What is the depth of the hole for KAMAZ-65115 (dump truck)

For KAMAZ-65115 with a clearance of 320 mm the optimal depth of the pit - 0.6-0.7 m. Note that the center of gravity of dump trucks is higher, so the ramp should be wider by 20 cm (at least 2.4 m). If you plan to maintain the unloading mechanism, make a local recess under the hydraulic cylinders (another +20 cm).

Can you build a hole in a garage with high groundwater?

Yes, but it will take:

1. Drainage system with pump (e.g., Grundfos Unilift KP 150).
2. Waterproofing 3-layer: ruberoid + penetrating insulation + membrane Planter.
3. Concrete with hydrophobic (e.g., Penetron Admix).

The cost of such works will increase by 30-40%, but this is the only way to avoid flooding.

What kind of concrete to choose for a pit under Scania R470 (40 tons)

For trucks with mass 40 tons use concrete M350 (B25) with a mandatory reinforcement of a rod of 16 mm. Recommended composition per 1 m3:

• Cement M500 - 400 kg.
• The crushed fraction of 20-40 mm - 1000 kg.
• Sand - 750 kg.
• Water, 200 liters.
• Polypropylene fibre - 0.6 kg.

Add the plasticizer. C-3 (1% of the weight of cement) to increase frost resistance.

Do I need to legalize a viewing hole in a private garage?

If the pit:

• 🔹 Deep. less than 1.8 m No legalization is required (provided that the garage is not in the water protection zone).
• 🔹 Deep. more than 1.8 m or in a garage for commercial use – it is necessary to agree on the Gosstroynadzor.

Legalization will require:

1. Project pit (can be ordered in any project organization).
2. Conclusion on the state of the soil (geological surveys).
3. Construction permit (if the garage is attached to the house).

How to make a hole warm for work in winter?

Insulation methods:

• 🔥 Warm floor: Infrared film Caleo Gold (power 150 W / m2) under the finishing coating.
• 🧱 Wall insulation: Styrofoam PSB-S-35 (5 cm thick) + plaster.
• 🚪 Heat curtain: Install at the garage entrance (e.g., Tropik T).
• 🔌 Heater: Diesel Master BV 77 E (for non-residential premises).

The optimum temperature for work: +15°C. At a lower temperature, the rubber seals of the tool lose elasticity.