BriggsB LLC designs bascule spans, pedestrian bridges and structural retrofits from its Ogden studio at 1118 W Excalibur Way, Ogden, 84401-5111, United States. Six services sit on one rack, and each one is delivered by the same small engineering group. A client can enter at any plate and still reach a stamped, buildable result.
Each plate below is a complete service with a defined deliverable. Together they carry a crossing from first reconnaissance to the day the leaf first opens.
A bascule span pivots on a trunnion so a waterway stays open to boats while the deck serves traffic. BriggsB LLC sizes the leaf, sets the trunnion center, balances the counterweight and details the riveted deck face for the cycle life the bridge will actually see. The service runs from concept layout through stamped construction drawings, and we model the opening motion as a load case in its own right.
Trails, campuses and river parks need crossings that feel calm underfoot. We select spans, control vibration, shape guardrails and design light foundations. Whether the answer is a simple plate girder or a small moving leaf, the goal is a structure that invites people onto it.
Older spans rarely need replacement; they need careful reading. Our assessments document corrosion, fatigue and movement, then rank repairs by cost and consequence. BriggsB LLC keeps retrofits buildable with local crews and familiar materials, so the fix lasts without a full reconstruction budget.
Legal capacity comes from careful arithmetic backed by measurement. We pair field inspection with analysis to state exactly what a structure carries today, and we flag the members that govern the number.
Drawings still need accurate points on the ground. We translate trunnion centers, bearing lines and deck elevations into field staking that a survey crew sets without guesswork, and we stay on call through erection and first cycle.
Before steel is bought, options must be compared on one basis. We weigh span types, navigational clearances and life cycle expense, then present the trade offs plainly so a board can decide with confidence.
LOAD RATEDBriggsB LLC opens its Winter Review slots for span feasibility studies — reserve a place before the gauge rises.
The rack shows the outline; the sections below show the substance. Every service is described in full so a client knows what arrives at the end of the engagement.
The work begins with the water. We record navigational clearance, current speed and the schedule of openings, then fix the leaf length and trunnion location that satisfy them. Structural analysis follows, covering dead load, live load, wind, and the dynamic case of the leaf in motion. The counterweight is balanced so the drive does not fight gravity, and the deck face is detailed with rivet seams that stiffen the plate and manage water. Deliverables include general arrangement drawings, connection details, trunnion and bearing specifications, the drive and control narrative, and a stamped set ready for bidding. BriggsB LLC treats the operator house and console as part of the machine, so the control path from lever to leaf is designed, not assumed.
Pedestrian structures live or die on comfort. We size spans for light loads but design for the vibration that walking introduces, because a deck that trembles is a deck people avoid. Guardrails are shaped to the sight line, not merely to the code minimum, and foundations are kept shallow where riverbanks must stay undisturbed. For trail systems that cross working waterways, we can fold a small lifting leaf into the same design so boats are never blocked. Deliverables include span selection studies, framing plans, railing details, foundation design and a construction specification tailored to local crews.
A retrofit assessment is a diagnosis before it is a prescription. Field work maps section loss, cracking, pack rust and out of plane movement across the trunnion, the floor beams and the deck panels. Analysis then identifies which members govern capacity and which are merely weathered. The report ranks repair options by cost, disruption and remaining life, and it names the option the owner should reject as clearly as the one to choose. BriggsB LLC favors repairs that a local fabricator can execute, because a clever detail nobody can build protects no one.
Load rating turns a structure into a number an authority can post. Our inspectors measure members, note section loss and record the condition of bearings and expansion joints. The analysis follows the governing method for the span type and produces a rating factor for each legal vehicle, with the controlling member identified. For moving spans we also rate the trunnion, the counterweight supports and the floor system under the rack load of the open position. The output is a rating report, a posting recommendation and a list of items that would raise the number if repaired.
Even an accurate drawing becomes a problem if the setting points are unclear. We prepare staking tables for trunnion centers, bearing lines, anchor bolt groups and deck elevations, and we coordinate them with the survey crew before steel arrives. During erection we answer requests for information within the day and review submittals against the design intent. When the leaf is first swung, we help confirm the balance and record the as built geometry so the maintenance file starts complete. This service closes the gap between the drawing set and the finished span.
A feasibility study answers whether a project should proceed and which form it should take. We compare at least three alternatives, ranging from a fixed high level crossing to a bascule leaf to a repaired existing structure. Each alternative carries an order of magnitude cost, a schedule, a right of way footprint and a life cycle estimate for maintenance and operations. Traffic and marine disruption are stated in plain terms. The study ends with a recommendation and the assumptions behind it, so a board can test the logic rather than trust a conclusion.
The six services are not separate silos. They ride the same sequence, and each stage hands the next a document it can rely on.
The engagement opens with reconnaissance, where field measurement and clearance records set the governing constraints. Feasibility and rating follow, comparing options and establishing capacity. Only then does design begin, first the trunnion and leaf geometry, then the counterweight travel, then the deck panels and the console. Detailing closes the loop with buildable connections and a specification a fabricator can price.
In the field, staking support carries the design to the ground. We set the points, answer questions and witness the first cycle. Because the same engineers who modeled the leaf also stand beside it when it moves, discrepancies surface early and corrections stay small.
Throughout, BriggsB LLC writes for the reader. Reports open with a one page summary, then support it with data. Drawings carry notes in plain language alongside the symbols. Clients never need a second consultant to interpret the first.
If you are planning a crossing or worried about one you already own, the rack is open. Reach the studio at hello@briggsb.lat, call +12672131249, or request a span study and we will start with a conversation about the water.