Tamping Rammers - Jumping Jacks

A tamping rammer (jumping jack) compacts soil with vertical impact of around 10–18 kN at 500–700 blows per minute, reaching layers of 40–60 cm. A plate compactor vibrates a plate and compacts thinner layers (usually 20–30 cm) over a large area. Choose a rammer for cohesive soils (clay, silt) and narrow trenches; choose a plate for granular soils, large areas and block paving.

A vibratory rammer performs best in cohesive soils — clay and silt — because vertical impact of 10–18 kN drives through layers where a plate slides. It also handles mixed soils and base courses. In granular soils (sand, gravel) over large areas a plate compactor is faster, but in narrow trenches the jumping jack takes over, compacting layers up to about 40–60 cm — thicker than the typical 20–30 cm for a plate.

Tamping rammers usually develop impact force in the range of 10–18 kN, work at 500–700 blows per minute and compact layers up to about 40–60 cm — models such as the Wacker Neuson BS 50-2 and BS 60-2 belong to this group. The foot stroke is roughly 40–85 mm, and the operating weight is usually 50–80 kg. Exact values for a given model are stated on its product page.

A trench rammer usually weighs 50–90 kg, and models for narrow trenches start at about 50–65 kg. Despite this weight, one person handles it — the operator guides the machine by the handles while the foot impact "carries" it forward. Transport wheels (for example on the Altrad Belle RTX), removed during work, make moving it easier, and anti-vibration gloves plus regular breaks are recommended because of the vibration.

A petrol rammer is driven by a petrol engine and gives long runtime without recharging. A battery rammer, such as the Wacker Neuson AS 50 e, works with zero emissions and more quietly — it produces no exhaust fumes, so it suits interiors, tunnels and unventilated trenches where fumes are dangerous. Impact force and the 500–700 blows per minute are close to petrol models in the same class; what differs is the power source.

4-stroke rammers are filled with clean unleaded petrol, and the engine oil (usually SAE 10W-30) is topped up separately in the sump. 2-stroke models run on a mix of petrol and 2-stroke oil in the ratio stated by the maker (typically 1:50). The rammer foot is lubricated separately with a dedicated oil, for example the oil for the Wacker Neuson BS 50-2 and BS 60-2 from our range. Check the oil grades for your model in the manual.

A tamping rammer is the go-to equipment for narrow trenches around pipelines, utility connections and foundations. A narrow foot about 150–350 mm wide fits between the shoring, and vertical impact of 10–18 kN compacts backfill in layers up to about 40–60 cm — something a wide plate compactor cannot do. This limits settlement of the soil above the installations. For such zones you pick a model with a narrower foot and a weight of 50–70 kg.

The price of a trench rammer depends on the brand, operating weight (usually 50–90 kg) and drive — professional petrol jumping jacks from Wacker Neuson or Bomag run into several thousand zloty, and battery models can cost more. Rental is charged per day, so for a one-off backfill it can be cheaper; with regular work a purchase pays for itself after several to a dozen or so working days in the season and gives constant access to the machine and consumables.

Starting a petrol rammer takes a few steps: set it upright, check the engine oil and foot oil levels, open the fuel valve and set the choke and throttle for starting. Pull the starter cord, once it fires ease the choke off and wait 1–2 minutes for warm-up. Add throttle — the foot strikes 500–700 times per minute; guide the rammer slowly, compacting in layers of 20–30 cm across 2–3 passes. A battery model starts with a button.

For the paving blocks themselves you usually use a plate compactor with a protective mat, which sets the blocks without scratching them. The tamping rammer comes in earlier — to compact the base course and bedding in trenches and narrow zones a plate cannot reach, in layers up to about 40–60 cm. The two tools complement each other: the jumping jack builds the base and edges, the plate finishes the surface. See our plate compactors for paving blocks, and for narrow base courses pick a rammer of 50–70 kg.