tramble

Trambling is the manual separation of tin ore from lighter waste material using a shovel and a shallow, sloped wooden frame fitted with riddles or grates. The worker fills the shovel with crushed ore and rock, then agitates it in water within the frame so that heavy tin particles settle while clay, sand, and lighter fragments wash away over the edge. The frame, called a tramble or trundle, sits at an angle to encourage gravity-driven separation.

The process depends entirely on particle density and water flow. Tin ore, being significantly denser than the surrounding country rock and clay, sinks quickly when agitated in suspension. The shovel itself serves as both the mixing tool and the means of controlling material flow through the frame. Workers develop a rhythmic, practiced motion: dip, stir, lift, and rake the settled heavy material back for re-washing or concentration.

Trambling originated in Cornish tin mining and remains widespread in alluvial and eluvial tin workings across southeast Asia and Africa. It is labour intensive but requires minimal capital: a frame, a shovel, access to running water or a constructed channel, and human effort. The method works best for relatively coarse ore; very fine material stays suspended longer and requires settling ponds or more sophisticated gravity concentration equipment downstream.

Variants include the use of buddies (another name for the washing frame in some regions) with different ridge patterns and slopes depending on the ore size distribution. Some operations use multiple trambles in series, each stage accepting the settled material from the previous one. Water management is critical; too little flow leaves ore clogged in clay, while excessive current carries away fine cassiterite prematurely.

The word likely derives from the trampling or vigorous agitation motion essential to the work, or from the frame itself being referred to as a tramble in regional mining dialect. The method represents the boundary between artisanal and semi-mechanized extraction, often appearing alongside simpler panning in the same operation.