Infrastructure Survey - Timbur Deep
Compiled for reference by Khuldinai engineering team for those who require accurate functional data on the settlement. The following reflects the city as observed, not as its administrators describe it. Aesthetic commentary has been omitted. Units and tolerances are noted where determinable.
Section 1 - Material Hierarchy and Structural Applications
Seven primary materials are in use across the settlement. Each is assigned to applications consistent with its load capacity, weathering tolerance, and availability. Deviations from this assignment pattern are common in lower districts and should be read as indicators of resource scarcity rather than engineering decisions.
Basalt (local, columnar extraction from caldera face)
Primary structural material. Load-bearing walls, foundations, road surfaces in upper districts. Columnar natural jointing eliminates mortar requirement in primary wall construction; gravity and mass provide joint integrity. Compressive strength adequate for multi-story construction at any realistic load. Thermal shock resistance high - formation temperature exceeds any credible fire event. Does not require cutting: natural fracture geometry produces usable building stock directly. Extraction site is the caldera wall immediately adjacent to the palace and Bastion. Transport distance negligible.
Road application: dressed basalt cobblestone in upper districts. Provides stable surface, high durability, non-negotiable maintenance requirement at zero cost beyond labor.
Tuff (local, consolidated caldera ash deposits)
Interior surfaces, dome shells, carved architectural detail. Lower compressive strength than basalt; not suitable for primary exterior load-bearing elements. Carveable with standard iron tools. Provides thermal insulation within dual-wall assemblies. Applied as interior skin on basalt structural walls - the air gap between basalt exterior and tuff interior functions as a passive insulation barrier without mechanical intervention.
Andesite (local, Dragon’s Spine volcanic system)
Middle district structural construction. Workable with iron tools without the tool degradation rate of basalt. Compressive strength adequate for residential and commercial construction at three to four stories. Weathers to a dark patina consistent with the city’s overall material character. More consistent than rhyolite, which presents internal fracture planes at unacceptable frequency for structural use. Rhyolite retained for decorative applications only.
Volcanic brick (local production, caldera ash clay source)
Lower middle districts. Produced from weathered volcanic ash deposits on the caldera floor - material availability is effectively unlimited given the catchment area. Fired in the industrial settlement’s kilns using methane vent output as fuel source. Consistent dimensions allow construction by semi-skilled labor. Structural ceiling: three stories at standard wall thickness. Quality varies by district based on firing temperature and mortar composition.
Scoria block (local, quarry waste from basalt extraction)
Lower districts. This material is free. It is byproduct material from basalt quarrying operations, previously treated as disposal problem. Its vesicular structure provides mechanical key for mortar adhesion superior to smooth stone surfaces, partially compensating for lower compressive strength. Structural ceiling: two to three stories. Not an engineering material - a scarcity material. Its use indicates absence of alternatives, not informed selection.
Potential road application: scoria gravel in Slums district. Loose, irregular, provides poor footing. Not maintained.
Imported granite (Khuldinai range, transport cost significant)
Ceremonial columns, Bastion structural elements requiring highest compressive performance. Polishes to surface finish unavailable in local volcanic materials. Transport cost from the Khuldinai range constitutes the primary economic argument against wider use. Applied where the statement of cost is itself a functional requirement.
Obsidian and imported marble
Palace prestige surfaces. Functional properties secondary to symbolic application. Obsidian facing on high-traffic ceremonial floors provides genuine hardness advantage. Marble provides carved detail finish quality unavailable in tuff. Both function as controlled resource expenditure by the imperial administration.
Other stone (imported, limited observed use)
Marble and limestone appear in the city in quantities consistent with high transport cost - present, but applied selectively. Sandstone has been described to this author but not observed directly in Timbur Deep construction.
Marble has been observed in carved decorative panels in upper-tier structures. Surface finish quality exceeds anything achievable with local tuff. Weathers poorly in sustained wet conditions. Appropriate for interior applications. Its presence in exterior-facing decorative work in Sable Rise suggests the owners are replacing it periodically or have not yet noticed the problem.
Limestone is lower grade, more variable in density and composition, but available in larger block sizes and at lower cost than marble. Observed in foundation and lower-course applications in several older structures in the middle districts, presumably placed before local supply chains were fully established. Performs adequately in compression. Performs poorly in the local climate over a century or more - surface erosion is visible on older installations. Not recommended for new construction where better materials are available.
Sandstone is reported to occur in the Heartlands plain where erosion has exposed older geology beneath the volcanic ash deposits. This author has not handled it in a Timbur Deep context. Its properties are variable by composition and cementation quality. It is soft enough to work easily with iron tools, which gives it appeal for carved detail, but the same softness makes it a poor structural stone in any wet climate. If it appears in the city it has not appeared in any structure I was asked to assess.
Section 2 - Water Supply
Source
Caldera rim catchment. Precipitation on the Dragon’s Spine peaks collects in the caldera depression and feeds the reservoir through surface runoff and subsurface spring systems. The reservoir sits at the caldera’s interior, elevated above all inhabited districts. No external pumping required at any point in the distribution system.
At a caldera diameter of approximately twelve kilometers and annual precipitation consistent with the regional climate pattern, the catchment generates several times the daily consumption requirement. Supply is not a constraint. Distribution is.
Distribution
Gravity-fed from reservoir south through the city. The elevation gradient from the reservoir at the Bastion level down to the Slums canal provides adequate pressure differential for passive distribution throughout the inhabited area. Pipe infrastructure - primarily lead-lined clay sections with stone joints - degrades over time. Middle district distribution quality correlates with infrastructure maintenance investment, which correlates with district economic status. The lower the district, the older and less maintained the pipe runs.
Quality by district
Bastion and Sable Rise: reservoir-direct. Water quality at source.
Guildstone Quarter and Ashvale: pipe-distributed, maintained infrastructure.
Market Lane and Larder’s End: older pipe runs, some joint cracking, quality degradation.
Slums: distribution from cisterns and standpipes. Canal water used for non-consumption purposes. Consumption from cistern draws - contamination risk during high-rain events when canal overflow reaches cistern intake zones.
Section 3 - Food Logistics
External supply - four ingest points
The supply system is designed around redundancy. No single ingest point failure produces a city-critical food shortage. This is correct engineering. Four independent catchment zones, independent transport routes, and independent failure modes.
Eastern river dock
Primary high-volume artery. Grain from Heartlands farms via barge, coastal goods via the same route. The eastern river is navigable from the city dock south to coast transfer terminal. It is not navigable north of the city - steep gradient, fast water, barge-incompatible.
Fixed stone bridge on the eastern road provides a navigation arch for barge passage. The arch controls maximum vessel dimensions - no sea-going ship passes it. Purpose-built river barges only. The bridge is also a controlled point for taxation and inspection.
Towpath runs continuously on the eastern bank, Timbur Deep to transfer terminal. Loaded barges upstream at two to three miles per hour behind horse or mule teams. Way stations at ten to fifteen mile intervals for animal exchange and crew rest. Upstream is slow. This is not a problem for grain.
The dock sits at Guildstone Quarter elevation, not base level. Goods arrive at middle elevation and distribute upward or downward from there. This reduces the internal vertical transport requirement significantly.
Western ferry
Western catchment: farms west of the Dragon’s Spine. Independent watershed from the eastern river. If the eastern river is disrupted, western ferry continues to function. Ferry transfer to the city from the western river approach.
Overland cart, direct Heartlands farms
Fifteen-mile effective radius from the city gate. Daily deliveries of perishables - vegetables, dairy, live animals. Items that do not survive barge transit. Multiple independent suppliers. No single choke point.
Internal Pens
Livestock bred and slaughtered within city boundaries. No external ingest point required. Primary protein source for general population.
Internal distribution - classified routing
A fifth supply line exists that does not interact with the civilian ingest points above.
The eastern supply route runs around the Dragon’s Spine northern foothills to local farms. Fresh produce, premium grain, and high-value goods arrive directly. The political class operates a supply chain independent of merchant House handling.
The Great Lifts on the western cliff face of the Legion compound provide a separate military supply chain from the western river approach. The compound can sustain itself during civil unrest. It cannot be pressured through food.
Both systems are safeguards to mitigate disruption of civilian supply.
Section 4 - Waste Management
Sewer system
Network of vaulted tunnels carved into the cliff escarpments, predating the current city. Collects waste from inhabited areas and channels it downhill to the canal at Slums base level. Lateral tunnel system, not vertical - it follows the cliff faces rather than dropping through them. Solid waste channels are routed directly to the cave system described below, the builders understood the underground geometry before the city was constructed above it.
The tunnel network serves a secondary function as a transit system for parties who require movement through the city without using street-level routes. This is known to the relevant parties and is not the subject of this document.
Canal
Base level, Slums district. Collects all surface drainage from the city above it, sewer overflow during high-rain events, and street wash from lower districts. The canal is not a water supply source. It should not be treated as one.
Wastewater pond
Southeastern edge of the city. Collects from the canal. Drains into the underground cave system below. This is not a storage facility - it is a transfer point. Volume held at surface is small because throughput to the underground system is continuous. At 400,000 population with full waste input, current throughput capacity sustains operation for several centuries before accumulation becomes a management problem. This number assumes no significant increase in population.
Underground cave system
The liquid component seeps through the cave geology and enters an underground river running south and southeast below the eastern surface river. Solid organic waste undergoes anaerobic decomposition in cave chambers. Volume reduction through decomposition is ninety to ninety-five percent. Residual mineral accumulation is negligible at current population levels over any planning horizon relevant to the current administration.
The cave system itself is vast. Its full extent has not been determined and cannot be determined with current access and instrumentation. The deep system is not navigable by any standard method - gas accumulation in enclosed chambers at depth produces immediate combustion risk with open flame and incapacitation risk from displacement of breathable air in confined spaces. Primary access is controlled by the Legion compound. The compound’s interest in maintaining this control is both a security measure and a safety one.
Disease risk
Concentrated in the Slums. High population density, inadequate street-level waste separation from water sources, canal proximity. Epidemic events originate here at irregular intervals and move through the lower city. The upper districts are protected by the elevation gradient - the Bastion’s water source is upstream of all waste inputs. The Slums’ water source is downstream of the city’s entire waste output. This is not a new problem and has not been treated as a priority by the administration.
Section 5 - Elevation Profile
Referenced from canal base at 0 feet. All figures approximate.
| Level | District | Elevation |
|---|---|---|
| 0 | Slums canal / wastewater pond | 0 ft |
| 1 | First cliff break - Ashvale Heights / Market Lane | +80–100 ft |
| 2 | Second cliff break - Guildstone Quarter to Sable Rise | +110–150 ft |
| 3 | Bastion and Imperial Palace | +170–200 ft |
| - | Dragon’s Spine (northern boundary) | ascends sharply to 9000 ft and above |
The city cannot expand north or west. The Dragon’s Spine caldera rim is the hard boundary in both directions. All historical expansion has moved south and east. The Slums are the largest district by area and population and sit at the lowest elevation furthest from the mountain. This is the predictable result of those constraints operating over time.
This document reflects engineering observation and does not constitute a full survey. Sections on military infrastructure have been omitted. The underground system description is limited to what is functionally relevant to waste management; its full strategic implications are addressed elsewhere.